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package java.util;

import java.util.function.UnaryOperator;

An ordered collection (also known as a sequence).  The user of this
interface has precise control over where in the list each element is
inserted.  The user can access elements by their integer index (position in
the list), and search for elements in the list.
 Unlike sets, lists typically allow duplicate elements. More formally, lists typically allow pairs of elements e1 and e2 such that e1.equals(e2), and they typically allow multiple null elements if they allow null elements at all. It is not inconceivable that someone might wish to implement a list that prohibits duplicates, by throwing runtime exceptions when the user attempts to insert them, but we expect this usage to be rare.
 The List interface places additional stipulations, beyond those specified in the Collection interface, on the contracts of the iterator, add, remove, equals, and hashCode methods. Declarations for other inherited methods are also included here for convenience.
 The List interface provides four methods for positional (indexed) access to list elements. Lists (like Java arrays) are zero based. Note that these operations may execute in time proportional to the index value for some implementations (the LinkedList class, for example). Thus, iterating over the elements in a list is typically preferable to indexing through it if the caller does not know the implementation.
 The List interface provides a special iterator, called a ListIterator, that allows element insertion and replacement, and bidirectional access in addition to the normal operations that the Iterator interface provides. A method is provided to obtain a list iterator that starts at a specified position in the list.
 The List interface provides two methods to search for a specified object. From a performance standpoint, these methods should be used with caution. In many implementations they will perform costly linear searches.
 The List interface provides two methods to efficiently insert and remove multiple elements at an arbitrary point in the list.
 Note: While it is permissible for lists to contain themselves as elements, extreme caution is advised: the equals and hashCode methods are no longer well defined on such a list. 
Some list implementations have restrictions on the elements that they may contain. For example, some implementations prohibit null elements, and some have restrictions on the types of their elements. Attempting to add an ineligible element throws an unchecked exception, typically NullPointerException or ClassCastException. Attempting to query the presence of an ineligible element may throw an exception, or it may simply return false; some implementations will exhibit the former behavior and some will exhibit the latter. More generally, attempting an operation on an ineligible element whose completion would not result in the insertion of an ineligible element into the list may throw an exception or it may succeed, at the option of the implementation. Such exceptions are marked as "optional" in the specification for this interface. 
Unmodifiable Lists
The List.of and List.copyOf static factory methods provide a convenient way to create unmodifiable lists. The List instances created by these methods have the following characteristics: 

They are unmodifiable. Elements cannot be added, removed, or replaced. Calling any mutator method on the List will always cause UnsupportedOperationException to be thrown. However, if the contained elements are themselves mutable, this may cause the List's contents to appear to change. 
They disallow null elements. Attempts to create them with null elements result in NullPointerException. 
They are serializable if all elements are serializable.
The order of elements in the list is the same as the order of the
provided arguments, or of the elements in the provided array.
They are value-based. Callers should make no assumptions about the identity of the returned instances. Factories are free to create new instances or reuse existing ones. Therefore, identity-sensitive operations on these instances (reference equality (==), identity hash code, and synchronization) are unreliable and should be avoided. 
They are serialized as specified on the
Serialized Form
page.

This interface is a member of the

Java Collections Framework.
Author:
 Josh Bloch,  Neal Gafter
Type parameters:
<E> – the type of elements in this list
See Also:
Collection
Set
ArrayList
LinkedList
Vector
Arrays.asList(Object[])
Collections.nCopies(int, Object)
Collections.EMPTY_LIST
AbstractList
AbstractSequentialList
Since:
1.2/**
 * An ordered collection (also known as a <i>sequence</i>).  The user of this
 * interface has precise control over where in the list each element is
 * inserted.  The user can access elements by their integer index (position in
 * the list), and search for elements in the list.<p>
 *
 * Unlike sets, lists typically allow duplicate elements.  More formally,
 * lists typically allow pairs of elements {@code e1} and {@code e2}
 * such that {@code e1.equals(e2)}, and they typically allow multiple
 * null elements if they allow null elements at all.  It is not inconceivable
 * that someone might wish to implement a list that prohibits duplicates, by
 * throwing runtime exceptions when the user attempts to insert them, but we
 * expect this usage to be rare.<p>
 *
 * The {@code List} interface places additional stipulations, beyond those
 * specified in the {@code Collection} interface, on the contracts of the
 * {@code iterator}, {@code add}, {@code remove}, {@code equals}, and
 * {@code hashCode} methods.  Declarations for other inherited methods are
 * also included here for convenience.<p>
 *
 * The {@code List} interface provides four methods for positional (indexed)
 * access to list elements.  Lists (like Java arrays) are zero based.  Note
 * that these operations may execute in time proportional to the index value
 * for some implementations (the {@code LinkedList} class, for
 * example). Thus, iterating over the elements in a list is typically
 * preferable to indexing through it if the caller does not know the
 * implementation.<p>
 *
 * The {@code List} interface provides a special iterator, called a
 * {@code ListIterator}, that allows element insertion and replacement, and
 * bidirectional access in addition to the normal operations that the
 * {@code Iterator} interface provides.  A method is provided to obtain a
 * list iterator that starts at a specified position in the list.<p>
 *
 * The {@code List} interface provides two methods to search for a specified
 * object.  From a performance standpoint, these methods should be used with
 * caution.  In many implementations they will perform costly linear
 * searches.<p>
 *
 * The {@code List} interface provides two methods to efficiently insert and
 * remove multiple elements at an arbitrary point in the list.<p>
 *
 * Note: While it is permissible for lists to contain themselves as elements,
 * extreme caution is advised: the {@code equals} and {@code hashCode}
 * methods are no longer well defined on such a list.
 *
 * <p>Some list implementations have restrictions on the elements that
 * they may contain.  For example, some implementations prohibit null elements,
 * and some have restrictions on the types of their elements.  Attempting to
 * add an ineligible element throws an unchecked exception, typically
 * {@code NullPointerException} or {@code ClassCastException}.  Attempting
 * to query the presence of an ineligible element may throw an exception,
 * or it may simply return false; some implementations will exhibit the former
 * behavior and some will exhibit the latter.  More generally, attempting an
 * operation on an ineligible element whose completion would not result in
 * the insertion of an ineligible element into the list may throw an
 * exception or it may succeed, at the option of the implementation.
 * Such exceptions are marked as "optional" in the specification for this
 * interface.
 *
 * <h2><a id="unmodifiable">Unmodifiable Lists</a></h2>
 * <p>The {@link List#of(Object...) List.of} and
 * {@link List#copyOf List.copyOf} static factory methods
 * provide a convenient way to create unmodifiable lists. The {@code List}
 * instances created by these methods have the following characteristics:
 *
 * <ul>
 * <li>They are <a href="Collection.html#unmodifiable"><i>unmodifiable</i></a>. Elements cannot
 * be added, removed, or replaced. Calling any mutator method on the List
 * will always cause {@code UnsupportedOperationException} to be thrown.
 * However, if the contained elements are themselves mutable,
 * this may cause the List's contents to appear to change.
 * <li>They disallow {@code null} elements. Attempts to create them with
 * {@code null} elements result in {@code NullPointerException}.
 * <li>They are serializable if all elements are serializable.
 * <li>The order of elements in the list is the same as the order of the
 * provided arguments, or of the elements in the provided array.
 * <li>They are <a href="../lang/doc-files/ValueBased.html">value-based</a>.
 * Callers should make no assumptions about the identity of the returned instances.
 * Factories are free to create new instances or reuse existing ones. Therefore,
 * identity-sensitive operations on these instances (reference equality ({@code ==}),
 * identity hash code, and synchronization) are unreliable and should be avoided.
 * <li>They are serialized as specified on the
 * <a href="{@docRoot}/serialized-form.html#java.util.CollSer">Serialized Form</a>
 * page.
 * </ul>
 *
 * <p>This interface is a member of the
 * <a href="{@docRoot}/java.base/java/util/package-summary.html#CollectionsFramework">
 * Java Collections Framework</a>.
 *
 * @param <E> the type of elements in this list
 *
 * @author  Josh Bloch
 * @author  Neal Gafter
 * @see Collection
 * @see Set
 * @see ArrayList
 * @see LinkedList
 * @see Vector
 * @see Arrays#asList(Object[])
 * @see Collections#nCopies(int, Object)
 * @see Collections#EMPTY_LIST
 * @see AbstractList
 * @see AbstractSequentialList
 * @since 1.2
 */

public interface List<E> extends Collection<E> {
    // Query Operations

    
Returns the number of elements in this list. If this list contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE. 
Returns:
the number of elements in this list/**
     * Returns the number of elements in this list.  If this list contains
     * more than {@code Integer.MAX_VALUE} elements, returns
     * {@code Integer.MAX_VALUE}.
     *
     * @return the number of elements in this list
     */
    int size();

    
Returns true if this list contains no elements. 
Returns:
true if this list contains no elements/**
     * Returns {@code true} if this list contains no elements.
     *
     * @return {@code true} if this list contains no elements
     */
    boolean isEmpty();

    
Returns true if this list contains the specified element. More formally, returns true if and only if this list contains at least one element e such that Objects.equals(o, e). 
Params:
o – element whose presence in this list is to be tested
Throws:
ClassCastException – if the type of the specified element
        is incompatible with this list
(optional)
NullPointerException – if the specified element is null and this
        list does not permit null elements
(optional)
Returns:
true if this list contains the specified element/**
     * Returns {@code true} if this list contains the specified element.
     * More formally, returns {@code true} if and only if this list contains
     * at least one element {@code e} such that
     * {@code Objects.equals(o, e)}.
     *
     * @param o element whose presence in this list is to be tested
     * @return {@code true} if this list contains the specified element
     * @throws ClassCastException if the type of the specified element
     *         is incompatible with this list
     * (<a href="Collection.html#optional-restrictions">optional</a>)
     * @throws NullPointerException if the specified element is null and this
     *         list does not permit null elements
     * (<a href="Collection.html#optional-restrictions">optional</a>)
     */
    boolean contains(Object o);

    
Returns an iterator over the elements in this list in proper sequence.
Returns:
an iterator over the elements in this list in proper sequence/**
     * Returns an iterator over the elements in this list in proper sequence.
     *
     * @return an iterator over the elements in this list in proper sequence
     */
    Iterator<E> iterator();

    
Returns an array containing all of the elements in this list in proper
sequence (from first to last element).
The returned array will be "safe" in that no references to it are
maintained by this list.  (In other words, this method must
allocate a new array even if this list is backed by an array).
The caller is thus free to modify the returned array.
This method acts as bridge between array-based and collection-based
APIs.
See Also:
Arrays.asList(Object[])
Returns:
an array containing all of the elements in this list in proper
        sequence/**
     * Returns an array containing all of the elements in this list in proper
     * sequence (from first to last element).
     *
     * <p>The returned array will be "safe" in that no references to it are
     * maintained by this list.  (In other words, this method must
     * allocate a new array even if this list is backed by an array).
     * The caller is thus free to modify the returned array.
     *
     * <p>This method acts as bridge between array-based and collection-based
     * APIs.
     *
     * @return an array containing all of the elements in this list in proper
     *         sequence
     * @see Arrays#asList(Object[])
     */
    Object[] toArray();

    
Returns an array containing all of the elements in this list in
proper sequence (from first to last element); the runtime type of
the returned array is that of the specified array.  If the list fits
in the specified array, it is returned therein.  Otherwise, a new
array is allocated with the runtime type of the specified array and
the size of this list.
If the list fits in the specified array with room to spare (i.e., the array has more elements than the list), the element in the array immediately following the end of the list is set to null. (This is useful in determining the length of the list only if
the caller knows that the list does not contain any null elements.)
Like the toArray() method, this method acts as bridge between array-based and collection-based APIs. Further, this method allows precise control over the runtime type of the output array, and may, under certain circumstances, be used to save allocation costs. 
Suppose x is a list known to contain only strings. The following code can be used to dump the list into a newly allocated array of String: 

    String[] y = x.toArray(new String[0]);
 Note that toArray(new Object[0]) is identical in function to toArray(). 
Params:
a – the array into which the elements of this list are to
         be stored, if it is big enough; otherwise, a new array of the
         same runtime type is allocated for this purpose.
Throws:
ArrayStoreException – if the runtime type of the specified array
        is not a supertype of the runtime type of every element in
        this list
NullPointerException – if the specified array is null
Returns:
an array containing the elements of this list/**
     * Returns an array containing all of the elements in this list in
     * proper sequence (from first to last element); the runtime type of
     * the returned array is that of the specified array.  If the list fits
     * in the specified array, it is returned therein.  Otherwise, a new
     * array is allocated with the runtime type of the specified array and
     * the size of this list.
     *
     * <p>If the list fits in the specified array with room to spare (i.e.,
     * the array has more elements than the list), the element in the array
     * immediately following the end of the list is set to {@code null}.
     * (This is useful in determining the length of the list <i>only</i> if
     * the caller knows that the list does not contain any null elements.)
     *
     * <p>Like the {@link #toArray()} method, this method acts as bridge between
     * array-based and collection-based APIs.  Further, this method allows
     * precise control over the runtime type of the output array, and may,
     * under certain circumstances, be used to save allocation costs.
     *
     * <p>Suppose {@code x} is a list known to contain only strings.
     * The following code can be used to dump the list into a newly
     * allocated array of {@code String}:
     *
     * <pre>{@code
     *     String[] y = x.toArray(new String[0]);
     * }</pre>
     *
     * Note that {@code toArray(new Object[0])} is identical in function to
     * {@code toArray()}.
     *
     * @param a the array into which the elements of this list are to
     *          be stored, if it is big enough; otherwise, a new array of the
     *          same runtime type is allocated for this purpose.
     * @return an array containing the elements of this list
     * @throws ArrayStoreException if the runtime type of the specified array
     *         is not a supertype of the runtime type of every element in
     *         this list
     * @throws NullPointerException if the specified array is null
     */
    <T> T[] toArray(T[] a);


    // Modification Operations

    
Appends the specified element to the end of this list (optional
operation).
Lists that support this operation may place limitations on what
elements may be added to this list.  In particular, some
lists will refuse to add null elements, and others will impose
restrictions on the type of elements that may be added.  List
classes should clearly specify in their documentation any restrictions
on what elements may be added.
Params:
e – element to be appended to this list
Throws:
UnsupportedOperationException – if the add operation is not supported by this list
ClassCastException – if the class of the specified element
        prevents it from being added to this list
NullPointerException – if the specified element is null and this
        list does not permit null elements
IllegalArgumentException – if some property of this element
        prevents it from being added to this list
Returns:
true (as specified by Collection.add)/**
     * Appends the specified element to the end of this list (optional
     * operation).
     *
     * <p>Lists that support this operation may place limitations on what
     * elements may be added to this list.  In particular, some
     * lists will refuse to add null elements, and others will impose
     * restrictions on the type of elements that may be added.  List
     * classes should clearly specify in their documentation any restrictions
     * on what elements may be added.
     *
     * @param e element to be appended to this list
     * @return {@code true} (as specified by {@link Collection#add})
     * @throws UnsupportedOperationException if the {@code add} operation
     *         is not supported by this list
     * @throws ClassCastException if the class of the specified element
     *         prevents it from being added to this list
     * @throws NullPointerException if the specified element is null and this
     *         list does not permit null elements
     * @throws IllegalArgumentException if some property of this element
     *         prevents it from being added to this list
     */
    boolean add(E e);

    
Removes the first occurrence of the specified element from this list, if it is present (optional operation). If this list does not contain the element, it is unchanged. More formally, removes the element with the lowest index i such that Objects.equals(o, get(i)) (if such an element exists). Returns true if this list contained the specified element (or equivalently, if this list changed as a result of the call). 
Params:
o – element to be removed from this list, if present
Throws:
ClassCastException – if the type of the specified element
        is incompatible with this list
(optional)
NullPointerException – if the specified element is null and this
        list does not permit null elements
(optional)
UnsupportedOperationException – if the remove operation is not supported by this list
Returns:
true if this list contained the specified element/**
     * Removes the first occurrence of the specified element from this list,
     * if it is present (optional operation).  If this list does not contain
     * the element, it is unchanged.  More formally, removes the element with
     * the lowest index {@code i} such that
     * {@code Objects.equals(o, get(i))}
     * (if such an element exists).  Returns {@code true} if this list
     * contained the specified element (or equivalently, if this list changed
     * as a result of the call).
     *
     * @param o element to be removed from this list, if present
     * @return {@code true} if this list contained the specified element
     * @throws ClassCastException if the type of the specified element
     *         is incompatible with this list
     * (<a href="Collection.html#optional-restrictions">optional</a>)
     * @throws NullPointerException if the specified element is null and this
     *         list does not permit null elements
     * (<a href="Collection.html#optional-restrictions">optional</a>)
     * @throws UnsupportedOperationException if the {@code remove} operation
     *         is not supported by this list
     */
    boolean remove(Object o);


    // Bulk Modification Operations

    
Returns true if this list contains all of the elements of the specified collection. 
Params:
c – collection to be checked for containment in this list
Throws:
ClassCastException – if the types of one or more elements
        in the specified collection are incompatible with this
        list
(optional)
NullPointerException – if the specified collection contains one
        or more null elements and this list does not permit null
        elements
        (optional),
        or if the specified collection is null
See Also:
contains(Object)
Returns:
true if this list contains all of the elements of the specified collection/**
     * Returns {@code true} if this list contains all of the elements of the
     * specified collection.
     *
     * @param  c collection to be checked for containment in this list
     * @return {@code true} if this list contains all of the elements of the
     *         specified collection
     * @throws ClassCastException if the types of one or more elements
     *         in the specified collection are incompatible with this
     *         list
     * (<a href="Collection.html#optional-restrictions">optional</a>)
     * @throws NullPointerException if the specified collection contains one
     *         or more null elements and this list does not permit null
     *         elements
     *         (<a href="Collection.html#optional-restrictions">optional</a>),
     *         or if the specified collection is null
     * @see #contains(Object)
     */
    boolean containsAll(Collection<?> c);

    
Appends all of the elements in the specified collection to the end of
this list, in the order that they are returned by the specified
collection's iterator (optional operation).  The behavior of this
operation is undefined if the specified collection is modified while
the operation is in progress.  (Note that this will occur if the
specified collection is this list, and it's nonempty.)
Params:
c – collection containing elements to be added to this list
Throws:
UnsupportedOperationException – if the addAll operation is not supported by this list
ClassCastException – if the class of an element of the specified
        collection prevents it from being added to this list
NullPointerException – if the specified collection contains one
        or more null elements and this list does not permit null
        elements, or if the specified collection is null
IllegalArgumentException – if some property of an element of the
        specified collection prevents it from being added to this list
See Also:
add(Object)
Returns:
true if this list changed as a result of the call/**
     * Appends all of the elements in the specified collection to the end of
     * this list, in the order that they are returned by the specified
     * collection's iterator (optional operation).  The behavior of this
     * operation is undefined if the specified collection is modified while
     * the operation is in progress.  (Note that this will occur if the
     * specified collection is this list, and it's nonempty.)
     *
     * @param c collection containing elements to be added to this list
     * @return {@code true} if this list changed as a result of the call
     * @throws UnsupportedOperationException if the {@code addAll} operation
     *         is not supported by this list
     * @throws ClassCastException if the class of an element of the specified
     *         collection prevents it from being added to this list
     * @throws NullPointerException if the specified collection contains one
     *         or more null elements and this list does not permit null
     *         elements, or if the specified collection is null
     * @throws IllegalArgumentException if some property of an element of the
     *         specified collection prevents it from being added to this list
     * @see #add(Object)
     */
    boolean addAll(Collection<? extends E> c);

    
Inserts all of the elements in the specified collection into this
list at the specified position (optional operation).  Shifts the
element currently at that position (if any) and any subsequent
elements to the right (increases their indices).  The new elements
will appear in this list in the order that they are returned by the
specified collection's iterator.  The behavior of this operation is
undefined if the specified collection is modified while the
operation is in progress.  (Note that this will occur if the specified
collection is this list, and it's nonempty.)
Params:
index – index at which to insert the first element from the
             specified collection
c – collection containing elements to be added to this list
Throws:
UnsupportedOperationException – if the addAll operation is not supported by this list
ClassCastException – if the class of an element of the specified
        collection prevents it from being added to this list
NullPointerException – if the specified collection contains one
        or more null elements and this list does not permit null
        elements, or if the specified collection is null
IllegalArgumentException – if some property of an element of the
        specified collection prevents it from being added to this list
IndexOutOfBoundsException – if the index is out of range (index < 0 || index > size())
Returns:
true if this list changed as a result of the call/**
     * Inserts all of the elements in the specified collection into this
     * list at the specified position (optional operation).  Shifts the
     * element currently at that position (if any) and any subsequent
     * elements to the right (increases their indices).  The new elements
     * will appear in this list in the order that they are returned by the
     * specified collection's iterator.  The behavior of this operation is
     * undefined if the specified collection is modified while the
     * operation is in progress.  (Note that this will occur if the specified
     * collection is this list, and it's nonempty.)
     *
     * @param index index at which to insert the first element from the
     *              specified collection
     * @param c collection containing elements to be added to this list
     * @return {@code true} if this list changed as a result of the call
     * @throws UnsupportedOperationException if the {@code addAll} operation
     *         is not supported by this list
     * @throws ClassCastException if the class of an element of the specified
     *         collection prevents it from being added to this list
     * @throws NullPointerException if the specified collection contains one
     *         or more null elements and this list does not permit null
     *         elements, or if the specified collection is null
     * @throws IllegalArgumentException if some property of an element of the
     *         specified collection prevents it from being added to this list
     * @throws IndexOutOfBoundsException if the index is out of range
     *         ({@code index < 0 || index > size()})
     */
    boolean addAll(int index, Collection<? extends E> c);

    
Removes from this list all of its elements that are contained in the
specified collection (optional operation).
Params:
c – collection containing elements to be removed from this list
Throws:
UnsupportedOperationException – if the removeAll operation is not supported by this list
ClassCastException – if the class of an element of this list
        is incompatible with the specified collection
(optional)
NullPointerException – if this list contains a null element and the
        specified collection does not permit null elements
        (optional),
        or if the specified collection is null
See Also:
remove(Object)
contains(Object)
Returns:
true if this list changed as a result of the call/**
     * Removes from this list all of its elements that are contained in the
     * specified collection (optional operation).
     *
     * @param c collection containing elements to be removed from this list
     * @return {@code true} if this list changed as a result of the call
     * @throws UnsupportedOperationException if the {@code removeAll} operation
     *         is not supported by this list
     * @throws ClassCastException if the class of an element of this list
     *         is incompatible with the specified collection
     * (<a href="Collection.html#optional-restrictions">optional</a>)
     * @throws NullPointerException if this list contains a null element and the
     *         specified collection does not permit null elements
     *         (<a href="Collection.html#optional-restrictions">optional</a>),
     *         or if the specified collection is null
     * @see #remove(Object)
     * @see #contains(Object)
     */
    boolean removeAll(Collection<?> c);

    
Retains only the elements in this list that are contained in the
specified collection (optional operation).  In other words, removes
from this list all of its elements that are not contained in the
specified collection.
Params:
c – collection containing elements to be retained in this list
Throws:
UnsupportedOperationException – if the retainAll operation is not supported by this list
ClassCastException – if the class of an element of this list
        is incompatible with the specified collection
(optional)
NullPointerException – if this list contains a null element and the
        specified collection does not permit null elements
        (optional),
        or if the specified collection is null
See Also:
remove(Object)
contains(Object)
Returns:
true if this list changed as a result of the call/**
     * Retains only the elements in this list that are contained in the
     * specified collection (optional operation).  In other words, removes
     * from this list all of its elements that are not contained in the
     * specified collection.
     *
     * @param c collection containing elements to be retained in this list
     * @return {@code true} if this list changed as a result of the call
     * @throws UnsupportedOperationException if the {@code retainAll} operation
     *         is not supported by this list
     * @throws ClassCastException if the class of an element of this list
     *         is incompatible with the specified collection
     * (<a href="Collection.html#optional-restrictions">optional</a>)
     * @throws NullPointerException if this list contains a null element and the
     *         specified collection does not permit null elements
     *         (<a href="Collection.html#optional-restrictions">optional</a>),
     *         or if the specified collection is null
     * @see #remove(Object)
     * @see #contains(Object)
     */
    boolean retainAll(Collection<?> c);

    
Replaces each element of this list with the result of applying the
operator to that element.  Errors or runtime exceptions thrown by
the operator are relayed to the caller.
Params:
operator – the operator to apply to each element
Throws:
UnsupportedOperationException – if this list is unmodifiable.
        Implementations may throw this exception if an element
        cannot be replaced or if, in general, modification is not
        supported
NullPointerException – if the specified operator is null or
        if the operator result is a null value and this list does
        not permit null elements
        (optional)
Implementation Requirements:
 The default implementation is equivalent to, for this list: 

    final ListIterator<E> li = list.listIterator();
    while (li.hasNext()) {
        li.set(operator.apply(li.next()));
    }
 If the list's list-iterator does not support the set operation then an UnsupportedOperationException will be thrown when replacing the first element.
Since:
1.8/**
     * Replaces each element of this list with the result of applying the
     * operator to that element.  Errors or runtime exceptions thrown by
     * the operator are relayed to the caller.
     *
     * @implSpec
     * The default implementation is equivalent to, for this {@code list}:
     * <pre>{@code
     *     final ListIterator<E> li = list.listIterator();
     *     while (li.hasNext()) {
     *         li.set(operator.apply(li.next()));
     *     }
     * }</pre>
     *
     * If the list's list-iterator does not support the {@code set} operation
     * then an {@code UnsupportedOperationException} will be thrown when
     * replacing the first element.
     *
     * @param operator the operator to apply to each element
     * @throws UnsupportedOperationException if this list is unmodifiable.
     *         Implementations may throw this exception if an element
     *         cannot be replaced or if, in general, modification is not
     *         supported
     * @throws NullPointerException if the specified operator is null or
     *         if the operator result is a null value and this list does
     *         not permit null elements
     *         (<a href="Collection.html#optional-restrictions">optional</a>)
     * @since 1.8
     */
    default void replaceAll(UnaryOperator<E> operator) {
        Objects.requireNonNull(operator);
        final ListIterator<E> li = this.listIterator();
        while (li.hasNext()) {
            li.set(operator.apply(li.next()));
        }
    }

    
Sorts this list according to the order induced by the specified Comparator. The sort is stable: this method must not
reorder equal elements.
All elements in this list must be mutually comparable using the specified comparator (that is, c.compare(e1, e2) must not throw a ClassCastException for any elements e1 and e2 in the list). 
If the specified comparator is null then all elements in this list must implement the Comparable interface and the elements' natural ordering should be used. 
This list must be modifiable, but need not be resizable.
Params:
c – the Comparator used to compare list elements. A null value indicates that the elements' natural ordering should be used
Throws:
ClassCastException – if the list contains elements that are not
        mutually comparable using the specified comparator
UnsupportedOperationException – if the list's list-iterator does not support the set operation
IllegalArgumentException – 
        (optional) if the comparator is found to violate the Comparator contract
Implementation Requirements:

The default implementation obtains an array containing all elements in
this list, sorts the array, and iterates over this list resetting each
element from the corresponding position in the array. (This avoids the
n2 log(n) performance that would result from attempting
to sort a linked list in place.)
Implementation Note:

This implementation is a stable, adaptive, iterative mergesort that
requires far fewer than n lg(n) comparisons when the input array is
partially sorted, while offering the performance of a traditional
mergesort when the input array is randomly ordered.  If the input array
is nearly sorted, the implementation requires approximately n
comparisons.  Temporary storage requirements vary from a small constant
for nearly sorted input arrays to n/2 object references for randomly
ordered input arrays.
The implementation takes equal advantage of ascending and
descending order in its input array, and can take advantage of
ascending and descending order in different parts of the same
input array.  It is well-suited to merging two or more sorted arrays:
simply concatenate the arrays and sort the resulting array.
The implementation was adapted from Tim Peters's list sort for Python
(
TimSort).  It uses techniques from Peter McIlroy's "Optimistic
Sorting and Information Theoretic Complexity", in Proceedings of the
Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
January 1993.
Since:
1.8/**
     * Sorts this list according to the order induced by the specified
     * {@link Comparator}.  The sort is <i>stable</i>: this method must not
     * reorder equal elements.
     *
     * <p>All elements in this list must be <i>mutually comparable</i> using the
     * specified comparator (that is, {@code c.compare(e1, e2)} must not throw
     * a {@code ClassCastException} for any elements {@code e1} and {@code e2}
     * in the list).
     *
     * <p>If the specified comparator is {@code null} then all elements in this
     * list must implement the {@link Comparable} interface and the elements'
     * {@linkplain Comparable natural ordering} should be used.
     *
     * <p>This list must be modifiable, but need not be resizable.
     *
     * @implSpec
     * The default implementation obtains an array containing all elements in
     * this list, sorts the array, and iterates over this list resetting each
     * element from the corresponding position in the array. (This avoids the
     * n<sup>2</sup> log(n) performance that would result from attempting
     * to sort a linked list in place.)
     *
     * @implNote
     * This implementation is a stable, adaptive, iterative mergesort that
     * requires far fewer than n lg(n) comparisons when the input array is
     * partially sorted, while offering the performance of a traditional
     * mergesort when the input array is randomly ordered.  If the input array
     * is nearly sorted, the implementation requires approximately n
     * comparisons.  Temporary storage requirements vary from a small constant
     * for nearly sorted input arrays to n/2 object references for randomly
     * ordered input arrays.
     *
     * <p>The implementation takes equal advantage of ascending and
     * descending order in its input array, and can take advantage of
     * ascending and descending order in different parts of the same
     * input array.  It is well-suited to merging two or more sorted arrays:
     * simply concatenate the arrays and sort the resulting array.
     *
     * <p>The implementation was adapted from Tim Peters's list sort for Python
     * (<a href="http://svn.python.org/projects/python/trunk/Objects/listsort.txt">
     * TimSort</a>).  It uses techniques from Peter McIlroy's "Optimistic
     * Sorting and Information Theoretic Complexity", in Proceedings of the
     * Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
     * January 1993.
     *
     * @param c the {@code Comparator} used to compare list elements.
     *          A {@code null} value indicates that the elements'
     *          {@linkplain Comparable natural ordering} should be used
     * @throws ClassCastException if the list contains elements that are not
     *         <i>mutually comparable</i> using the specified comparator
     * @throws UnsupportedOperationException if the list's list-iterator does
     *         not support the {@code set} operation
     * @throws IllegalArgumentException
     *         (<a href="Collection.html#optional-restrictions">optional</a>)
     *         if the comparator is found to violate the {@link Comparator}
     *         contract
     * @since 1.8
     */
    @SuppressWarnings({"unchecked", "rawtypes"})
    default void sort(Comparator<? super E> c) {
        Object[] a = this.toArray();
        Arrays.sort(a, (Comparator) c);
        ListIterator<E> i = this.listIterator();
        for (Object e : a) {
            i.next();
            i.set((E) e);
        }
    }

    
Removes all of the elements from this list (optional operation).
The list will be empty after this call returns.
Throws:
UnsupportedOperationException – if the clear operation is not supported by this list/**
     * Removes all of the elements from this list (optional operation).
     * The list will be empty after this call returns.
     *
     * @throws UnsupportedOperationException if the {@code clear} operation
     *         is not supported by this list
     */
    void clear();


    // Comparison and hashing

    
Compares the specified object with this list for equality. Returns true if and only if the specified object is also a list, both lists have the same size, and all corresponding pairs of elements in the two lists are equal. (Two elements e1 and e2 are equal if Objects.equals(e1, e2).) In other words, two lists are defined to be equal if they contain the same elements in the same order. This definition ensures that the equals method works properly across different implementations of the List interface. 
Params:
o – the object to be compared for equality with this list
Returns:
true if the specified object is equal to this list/**
     * Compares the specified object with this list for equality.  Returns
     * {@code true} if and only if the specified object is also a list, both
     * lists have the same size, and all corresponding pairs of elements in
     * the two lists are <i>equal</i>.  (Two elements {@code e1} and
     * {@code e2} are <i>equal</i> if {@code Objects.equals(e1, e2)}.)
     * In other words, two lists are defined to be
     * equal if they contain the same elements in the same order.  This
     * definition ensures that the equals method works properly across
     * different implementations of the {@code List} interface.
     *
     * @param o the object to be compared for equality with this list
     * @return {@code true} if the specified object is equal to this list
     */
    boolean equals(Object o);

    
Returns the hash code value for this list.  The hash code of a list
is defined to be the result of the following calculation:

    int hashCode = 1;
    for (E e : list)
        hashCode = 31*hashCode + (e==null ? 0 : e.hashCode());
 This ensures that list1.equals(list2) implies that list1.hashCode()==list2.hashCode() for any two lists, list1 and list2, as required by the general contract of Object.hashCode. 
See Also:
Object.equals(Object)
equals(Object)
Returns:
the hash code value for this list/**
     * Returns the hash code value for this list.  The hash code of a list
     * is defined to be the result of the following calculation:
     * <pre>{@code
     *     int hashCode = 1;
     *     for (E e : list)
     *         hashCode = 31*hashCode + (e==null ? 0 : e.hashCode());
     * }</pre>
     * This ensures that {@code list1.equals(list2)} implies that
     * {@code list1.hashCode()==list2.hashCode()} for any two lists,
     * {@code list1} and {@code list2}, as required by the general
     * contract of {@link Object#hashCode}.
     *
     * @return the hash code value for this list
     * @see Object#equals(Object)
     * @see #equals(Object)
     */
    int hashCode();


    // Positional Access Operations

    
Returns the element at the specified position in this list.
Params:
index – index of the element to return
Throws:
IndexOutOfBoundsException – if the index is out of range (index < 0 || index >= size())
Returns:
the element at the specified position in this list/**
     * Returns the element at the specified position in this list.
     *
     * @param index index of the element to return
     * @return the element at the specified position in this list
     * @throws IndexOutOfBoundsException if the index is out of range
     *         ({@code index < 0 || index >= size()})
     */
    E get(int index);

    
Replaces the element at the specified position in this list with the
specified element (optional operation).
Params:
index – index of the element to replace
element – element to be stored at the specified position
Throws:
UnsupportedOperationException – if the set operation is not supported by this list
ClassCastException – if the class of the specified element
        prevents it from being added to this list
NullPointerException – if the specified element is null and
        this list does not permit null elements
IllegalArgumentException – if some property of the specified
        element prevents it from being added to this list
IndexOutOfBoundsException – if the index is out of range (index < 0 || index >= size())
Returns:
the element previously at the specified position/**
     * Replaces the element at the specified position in this list with the
     * specified element (optional operation).
     *
     * @param index index of the element to replace
     * @param element element to be stored at the specified position
     * @return the element previously at the specified position
     * @throws UnsupportedOperationException if the {@code set} operation
     *         is not supported by this list
     * @throws ClassCastException if the class of the specified element
     *         prevents it from being added to this list
     * @throws NullPointerException if the specified element is null and
     *         this list does not permit null elements
     * @throws IllegalArgumentException if some property of the specified
     *         element prevents it from being added to this list
     * @throws IndexOutOfBoundsException if the index is out of range
     *         ({@code index < 0 || index >= size()})
     */
    E set(int index, E element);

    
Inserts the specified element at the specified position in this list
(optional operation).  Shifts the element currently at that position
(if any) and any subsequent elements to the right (adds one to their
indices).
Params:
index – index at which the specified element is to be inserted
element – element to be inserted
Throws:
UnsupportedOperationException – if the add operation is not supported by this list
ClassCastException – if the class of the specified element
        prevents it from being added to this list
NullPointerException – if the specified element is null and
        this list does not permit null elements
IllegalArgumentException – if some property of the specified
        element prevents it from being added to this list
IndexOutOfBoundsException – if the index is out of range (index < 0 || index > size())/**
     * Inserts the specified element at the specified position in this list
     * (optional operation).  Shifts the element currently at that position
     * (if any) and any subsequent elements to the right (adds one to their
     * indices).
     *
     * @param index index at which the specified element is to be inserted
     * @param element element to be inserted
     * @throws UnsupportedOperationException if the {@code add} operation
     *         is not supported by this list
     * @throws ClassCastException if the class of the specified element
     *         prevents it from being added to this list
     * @throws NullPointerException if the specified element is null and
     *         this list does not permit null elements
     * @throws IllegalArgumentException if some property of the specified
     *         element prevents it from being added to this list
     * @throws IndexOutOfBoundsException if the index is out of range
     *         ({@code index < 0 || index > size()})
     */
    void add(int index, E element);

    
Removes the element at the specified position in this list (optional
operation).  Shifts any subsequent elements to the left (subtracts one
from their indices).  Returns the element that was removed from the
list.
Params:
index – the index of the element to be removed
Throws:
UnsupportedOperationException – if the remove operation is not supported by this list
IndexOutOfBoundsException – if the index is out of range (index < 0 || index >= size())
Returns:
the element previously at the specified position/**
     * Removes the element at the specified position in this list (optional
     * operation).  Shifts any subsequent elements to the left (subtracts one
     * from their indices).  Returns the element that was removed from the
     * list.
     *
     * @param index the index of the element to be removed
     * @return the element previously at the specified position
     * @throws UnsupportedOperationException if the {@code remove} operation
     *         is not supported by this list
     * @throws IndexOutOfBoundsException if the index is out of range
     *         ({@code index < 0 || index >= size()})
     */
    E remove(int index);


    // Search Operations

    
Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element. More formally, returns the lowest index i such that Objects.equals(o, get(i)), or -1 if there is no such index. 
Params:
o – element to search for
Throws:
ClassCastException – if the type of the specified element
        is incompatible with this list
        (optional)
NullPointerException – if the specified element is null and this
        list does not permit null elements
        (optional)
Returns:
the index of the first occurrence of the specified element in
        this list, or -1 if this list does not contain the element/**
     * Returns the index of the first occurrence of the specified element
     * in this list, or -1 if this list does not contain the element.
     * More formally, returns the lowest index {@code i} such that
     * {@code Objects.equals(o, get(i))},
     * or -1 if there is no such index.
     *
     * @param o element to search for
     * @return the index of the first occurrence of the specified element in
     *         this list, or -1 if this list does not contain the element
     * @throws ClassCastException if the type of the specified element
     *         is incompatible with this list
     *         (<a href="Collection.html#optional-restrictions">optional</a>)
     * @throws NullPointerException if the specified element is null and this
     *         list does not permit null elements
     *         (<a href="Collection.html#optional-restrictions">optional</a>)
     */
    int indexOf(Object o);

    
Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element. More formally, returns the highest index i such that Objects.equals(o, get(i)), or -1 if there is no such index. 
Params:
o – element to search for
Throws:
ClassCastException – if the type of the specified element
        is incompatible with this list
        (optional)
NullPointerException – if the specified element is null and this
        list does not permit null elements
        (optional)
Returns:
the index of the last occurrence of the specified element in
        this list, or -1 if this list does not contain the element/**
     * Returns the index of the last occurrence of the specified element
     * in this list, or -1 if this list does not contain the element.
     * More formally, returns the highest index {@code i} such that
     * {@code Objects.equals(o, get(i))},
     * or -1 if there is no such index.
     *
     * @param o element to search for
     * @return the index of the last occurrence of the specified element in
     *         this list, or -1 if this list does not contain the element
     * @throws ClassCastException if the type of the specified element
     *         is incompatible with this list
     *         (<a href="Collection.html#optional-restrictions">optional</a>)
     * @throws NullPointerException if the specified element is null and this
     *         list does not permit null elements
     *         (<a href="Collection.html#optional-restrictions">optional</a>)
     */
    int lastIndexOf(Object o);


    // List Iterators

    
Returns a list iterator over the elements in this list (in proper
sequence).
Returns:
a list iterator over the elements in this list (in proper
        sequence)/**
     * Returns a list iterator over the elements in this list (in proper
     * sequence).
     *
     * @return a list iterator over the elements in this list (in proper
     *         sequence)
     */
    ListIterator<E> listIterator();

    
Returns a list iterator over the elements in this list (in proper sequence), starting at the specified position in the list. The specified index indicates the first element that would be returned by an initial call to next. An initial call to previous would return the element with the specified index minus one. 
Params:
index – index of the first element to be returned from the list iterator (by a call to next)
Throws:
IndexOutOfBoundsException – if the index is out of range (index < 0 || index > size())
Returns:
a list iterator over the elements in this list (in proper
        sequence), starting at the specified position in the list/**
     * Returns a list iterator over the elements in this list (in proper
     * sequence), starting at the specified position in the list.
     * The specified index indicates the first element that would be
     * returned by an initial call to {@link ListIterator#next next}.
     * An initial call to {@link ListIterator#previous previous} would
     * return the element with the specified index minus one.
     *
     * @param index index of the first element to be returned from the
     *        list iterator (by a call to {@link ListIterator#next next})
     * @return a list iterator over the elements in this list (in proper
     *         sequence), starting at the specified position in the list
     * @throws IndexOutOfBoundsException if the index is out of range
     *         ({@code index < 0 || index > size()})
     */
    ListIterator<E> listIterator(int index);

    // View

    
Returns a view of the portion of this list between the specified fromIndex, inclusive, and toIndex, exclusive. (If fromIndex and toIndex are equal, the returned list is empty.) The returned list is backed by this list, so non-structural changes in the returned list are reflected in this list, and vice-versa. The returned list supports all of the optional list operations supported by this list.

This method eliminates the need for explicit range operations (of
the sort that commonly exist for arrays).  Any operation that expects
a list can be used as a range operation by passing a subList view
instead of a whole list.  For example, the following idiom
removes a range of elements from a list:

     list.subList(from, to).clear();
 Similar idioms may be constructed for indexOf and lastIndexOf, and all of the algorithms in the Collections class can be applied to a subList.

The semantics of the list returned by this method become undefined if
the backing list (i.e., this list) is structurally modified in
any way other than via the returned list.  (Structural modifications are
those that change the size of this list, or otherwise perturb it in such
a fashion that iterations in progress may yield incorrect results.)
Params:
fromIndex – low endpoint (inclusive) of the subList
toIndex – high endpoint (exclusive) of the subList
Throws:
IndexOutOfBoundsException – for an illegal endpoint index value (fromIndex < 0 || toIndex > size ||
        fromIndex > toIndex)
Returns:
a view of the specified range within this list/**
     * Returns a view of the portion of this list between the specified
     * {@code fromIndex}, inclusive, and {@code toIndex}, exclusive.  (If
     * {@code fromIndex} and {@code toIndex} are equal, the returned list is
     * empty.)  The returned list is backed by this list, so non-structural
     * changes in the returned list are reflected in this list, and vice-versa.
     * The returned list supports all of the optional list operations supported
     * by this list.<p>
     *
     * This method eliminates the need for explicit range operations (of
     * the sort that commonly exist for arrays).  Any operation that expects
     * a list can be used as a range operation by passing a subList view
     * instead of a whole list.  For example, the following idiom
     * removes a range of elements from a list:
     * <pre>{@code
     *      list.subList(from, to).clear();
     * }</pre>
     * Similar idioms may be constructed for {@code indexOf} and
     * {@code lastIndexOf}, and all of the algorithms in the
     * {@code Collections} class can be applied to a subList.<p>
     *
     * The semantics of the list returned by this method become undefined if
     * the backing list (i.e., this list) is <i>structurally modified</i> in
     * any way other than via the returned list.  (Structural modifications are
     * those that change the size of this list, or otherwise perturb it in such
     * a fashion that iterations in progress may yield incorrect results.)
     *
     * @param fromIndex low endpoint (inclusive) of the subList
     * @param toIndex high endpoint (exclusive) of the subList
     * @return a view of the specified range within this list
     * @throws IndexOutOfBoundsException for an illegal endpoint index value
     *         ({@code fromIndex < 0 || toIndex > size ||
     *         fromIndex > toIndex})
     */
    List<E> subList(int fromIndex, int toIndex);

    
Creates a Spliterator over the elements in this list. 
The Spliterator reports Spliterator.SIZED and Spliterator.ORDERED. Implementations should document the reporting of additional characteristic values. 
Implementation Requirements:

The default implementation creates a
late-binding
spliterator as follows:

If the list is an instance of RandomAccess then the default implementation creates a spliterator that traverses elements by invoking the method get. If such invocation results or would result in an IndexOutOfBoundsException then the spliterator will fail-fast and throw a ConcurrentModificationException. If the list is also an instance of AbstractList then the spliterator will use the list's modCount field to provide additional fail-fast behavior.
Otherwise, the default implementation creates a spliterator from the list's Iterator. The spliterator inherits the fail-fast of the list's iterator.
Implementation Note:
 The created Spliterator additionally reports Spliterator.SUBSIZED.
Returns:
a Spliterator over the elements in this list
Since:
1.8/**
     * Creates a {@link Spliterator} over the elements in this list.
     *
     * <p>The {@code Spliterator} reports {@link Spliterator#SIZED} and
     * {@link Spliterator#ORDERED}.  Implementations should document the
     * reporting of additional characteristic values.
     *
     * @implSpec
     * The default implementation creates a
     * <em><a href="Spliterator.html#binding">late-binding</a></em>
     * spliterator as follows:
     * <ul>
     * <li>If the list is an instance of {@link RandomAccess} then the default
     *     implementation creates a spliterator that traverses elements by
     *     invoking the method {@link List#get}.  If such invocation results or
     *     would result in an {@code IndexOutOfBoundsException} then the
     *     spliterator will <em>fail-fast</em> and throw a
     *     {@code ConcurrentModificationException}.
     *     If the list is also an instance of {@link AbstractList} then the
     *     spliterator will use the list's {@link AbstractList#modCount modCount}
     *     field to provide additional <em>fail-fast</em> behavior.
     * <li>Otherwise, the default implementation creates a spliterator from the
     *     list's {@code Iterator}.  The spliterator inherits the
     *     <em>fail-fast</em> of the list's iterator.
     * </ul>
     *
     * @implNote
     * The created {@code Spliterator} additionally reports
     * {@link Spliterator#SUBSIZED}.
     *
     * @return a {@code Spliterator} over the elements in this list
     * @since 1.8
     */
    @Override
    default Spliterator<E> spliterator() {
        if (this instanceof RandomAccess) {
            return new AbstractList.RandomAccessSpliterator<>(this);
        } else {
            return Spliterators.spliterator(this, Spliterator.ORDERED);
        }
    }

    
Returns an unmodifiable list containing zero elements.
See Unmodifiable Lists for details.
Type parameters:
<E> – the List's element type
Returns:
an empty List
Since:
9/**
     * Returns an unmodifiable list containing zero elements.
     *
     * See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
     *
     * @param <E> the {@code List}'s element type
     * @return an empty {@code List}
     *
     * @since 9
     */
    static <E> List<E> of() {
        return ImmutableCollections.emptyList();
    }

    
Returns an unmodifiable list containing one element.
See Unmodifiable Lists for details.
Params:
e1 – the single element
Type parameters:
<E> – the List's element type
Throws:
NullPointerException – if the element is null
Returns:
a List containing the specified element
Since:
9/**
     * Returns an unmodifiable list containing one element.
     *
     * See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
     *
     * @param <E> the {@code List}'s element type
     * @param e1 the single element
     * @return a {@code List} containing the specified element
     * @throws NullPointerException if the element is {@code null}
     *
     * @since 9
     */
    static <E> List<E> of(E e1) {
        return new ImmutableCollections.List12<>(e1);
    }

    
Returns an unmodifiable list containing two elements.
See Unmodifiable Lists for details.
Params:
e1 – the first element
e2 – the second element
Type parameters:
<E> – the List's element type
Throws:
NullPointerException – if an element is null
Returns:
a List containing the specified elements
Since:
9/**
     * Returns an unmodifiable list containing two elements.
     *
     * See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
     *
     * @param <E> the {@code List}'s element type
     * @param e1 the first element
     * @param e2 the second element
     * @return a {@code List} containing the specified elements
     * @throws NullPointerException if an element is {@code null}
     *
     * @since 9
     */
    static <E> List<E> of(E e1, E e2) {
        return new ImmutableCollections.List12<>(e1, e2);
    }

    
Returns an unmodifiable list containing three elements.
See Unmodifiable Lists for details.
Params:
e1 – the first element
e2 – the second element
e3 – the third element
Type parameters:
<E> – the List's element type
Throws:
NullPointerException – if an element is null
Returns:
a List containing the specified elements
Since:
9/**
     * Returns an unmodifiable list containing three elements.
     *
     * See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
     *
     * @param <E> the {@code List}'s element type
     * @param e1 the first element
     * @param e2 the second element
     * @param e3 the third element
     * @return a {@code List} containing the specified elements
     * @throws NullPointerException if an element is {@code null}
     *
     * @since 9
     */
    static <E> List<E> of(E e1, E e2, E e3) {
        return new ImmutableCollections.ListN<>(e1, e2, e3);
    }

    
Returns an unmodifiable list containing four elements.
See Unmodifiable Lists for details.
Params:
e1 – the first element
e2 – the second element
e3 – the third element
e4 – the fourth element
Type parameters:
<E> – the List's element type
Throws:
NullPointerException – if an element is null
Returns:
a List containing the specified elements
Since:
9/**
     * Returns an unmodifiable list containing four elements.
     *
     * See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
     *
     * @param <E> the {@code List}'s element type
     * @param e1 the first element
     * @param e2 the second element
     * @param e3 the third element
     * @param e4 the fourth element
     * @return a {@code List} containing the specified elements
     * @throws NullPointerException if an element is {@code null}
     *
     * @since 9
     */
    static <E> List<E> of(E e1, E e2, E e3, E e4) {
        return new ImmutableCollections.ListN<>(e1, e2, e3, e4);
    }

    
Returns an unmodifiable list containing five elements.
See Unmodifiable Lists for details.
Params:
e1 – the first element
e2 – the second element
e3 – the third element
e4 – the fourth element
e5 – the fifth element
Type parameters:
<E> – the List's element type
Throws:
NullPointerException – if an element is null
Returns:
a List containing the specified elements
Since:
9/**
     * Returns an unmodifiable list containing five elements.
     *
     * See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
     *
     * @param <E> the {@code List}'s element type
     * @param e1 the first element
     * @param e2 the second element
     * @param e3 the third element
     * @param e4 the fourth element
     * @param e5 the fifth element
     * @return a {@code List} containing the specified elements
     * @throws NullPointerException if an element is {@code null}
     *
     * @since 9
     */
    static <E> List<E> of(E e1, E e2, E e3, E e4, E e5) {
        return new ImmutableCollections.ListN<>(e1, e2, e3, e4, e5);
    }

    
Returns an unmodifiable list containing six elements.
See Unmodifiable Lists for details.
Params:
e1 – the first element
e2 – the second element
e3 – the third element
e4 – the fourth element
e5 – the fifth element
e6 – the sixth element
Type parameters:
<E> – the List's element type
Throws:
NullPointerException – if an element is null
Returns:
a List containing the specified elements
Since:
9/**
     * Returns an unmodifiable list containing six elements.
     *
     * See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
     *
     * @param <E> the {@code List}'s element type
     * @param e1 the first element
     * @param e2 the second element
     * @param e3 the third element
     * @param e4 the fourth element
     * @param e5 the fifth element
     * @param e6 the sixth element
     * @return a {@code List} containing the specified elements
     * @throws NullPointerException if an element is {@code null}
     *
     * @since 9
     */
    static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6) {
        return new ImmutableCollections.ListN<>(e1, e2, e3, e4, e5,
                                                e6);
    }

    
Returns an unmodifiable list containing seven elements.
See Unmodifiable Lists for details.
Params:
e1 – the first element
e2 – the second element
e3 – the third element
e4 – the fourth element
e5 – the fifth element
e6 – the sixth element
e7 – the seventh element
Type parameters:
<E> – the List's element type
Throws:
NullPointerException – if an element is null
Returns:
a List containing the specified elements
Since:
9/**
     * Returns an unmodifiable list containing seven elements.
     *
     * See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
     *
     * @param <E> the {@code List}'s element type
     * @param e1 the first element
     * @param e2 the second element
     * @param e3 the third element
     * @param e4 the fourth element
     * @param e5 the fifth element
     * @param e6 the sixth element
     * @param e7 the seventh element
     * @return a {@code List} containing the specified elements
     * @throws NullPointerException if an element is {@code null}
     *
     * @since 9
     */
    static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7) {
        return new ImmutableCollections.ListN<>(e1, e2, e3, e4, e5,
                                                e6, e7);
    }

    
Returns an unmodifiable list containing eight elements.
See Unmodifiable Lists for details.
Params:
e1 – the first element
e2 – the second element
e3 – the third element
e4 – the fourth element
e5 – the fifth element
e6 – the sixth element
e7 – the seventh element
e8 – the eighth element
Type parameters:
<E> – the List's element type
Throws:
NullPointerException – if an element is null
Returns:
a List containing the specified elements
Since:
9/**
     * Returns an unmodifiable list containing eight elements.
     *
     * See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
     *
     * @param <E> the {@code List}'s element type
     * @param e1 the first element
     * @param e2 the second element
     * @param e3 the third element
     * @param e4 the fourth element
     * @param e5 the fifth element
     * @param e6 the sixth element
     * @param e7 the seventh element
     * @param e8 the eighth element
     * @return a {@code List} containing the specified elements
     * @throws NullPointerException if an element is {@code null}
     *
     * @since 9
     */
    static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8) {
        return new ImmutableCollections.ListN<>(e1, e2, e3, e4, e5,
                                                e6, e7, e8);
    }

    
Returns an unmodifiable list containing nine elements.
See Unmodifiable Lists for details.
Params:
e1 – the first element
e2 – the second element
e3 – the third element
e4 – the fourth element
e5 – the fifth element
e6 – the sixth element
e7 – the seventh element
e8 – the eighth element
e9 – the ninth element
Type parameters:
<E> – the List's element type
Throws:
NullPointerException – if an element is null
Returns:
a List containing the specified elements
Since:
9/**
     * Returns an unmodifiable list containing nine elements.
     *
     * See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
     *
     * @param <E> the {@code List}'s element type
     * @param e1 the first element
     * @param e2 the second element
     * @param e3 the third element
     * @param e4 the fourth element
     * @param e5 the fifth element
     * @param e6 the sixth element
     * @param e7 the seventh element
     * @param e8 the eighth element
     * @param e9 the ninth element
     * @return a {@code List} containing the specified elements
     * @throws NullPointerException if an element is {@code null}
     *
     * @since 9
     */
    static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9) {
        return new ImmutableCollections.ListN<>(e1, e2, e3, e4, e5,
                                                e6, e7, e8, e9);
    }

    
Returns an unmodifiable list containing ten elements.
See Unmodifiable Lists for details.
Params:
e1 – the first element
e2 – the second element
e3 – the third element
e4 – the fourth element
e5 – the fifth element
e6 – the sixth element
e7 – the seventh element
e8 – the eighth element
e9 – the ninth element
e10 – the tenth element
Type parameters:
<E> – the List's element type
Throws:
NullPointerException – if an element is null
Returns:
a List containing the specified elements
Since:
9/**
     * Returns an unmodifiable list containing ten elements.
     *
     * See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
     *
     * @param <E> the {@code List}'s element type
     * @param e1 the first element
     * @param e2 the second element
     * @param e3 the third element
     * @param e4 the fourth element
     * @param e5 the fifth element
     * @param e6 the sixth element
     * @param e7 the seventh element
     * @param e8 the eighth element
     * @param e9 the ninth element
     * @param e10 the tenth element
     * @return a {@code List} containing the specified elements
     * @throws NullPointerException if an element is {@code null}
     *
     * @since 9
     */
    static <E> List<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E e7, E e8, E e9, E e10) {
        return new ImmutableCollections.ListN<>(e1, e2, e3, e4, e5,
                                                e6, e7, e8, e9, e10);
    }

    
Returns an unmodifiable list containing an arbitrary number of elements.
See Unmodifiable Lists for details.
Params:
elements – the elements to be contained in the list
Type parameters:
<E> – the List's element type
Throws:
NullPointerException – if an element is null or if the array is null
API Note:

This method also accepts a single array as an argument. The element type of
the resulting list will be the component type of the array, and the size of
the list will be equal to the length of the array. To create a list with
a single element that is an array, do the following:

    String[] array = ... ;
    List<String[]> list = List.<String[]>of(array);
 This will cause the List.of(E) method to be invoked instead.
Returns:
a List containing the specified elements
Since:
9/**
     * Returns an unmodifiable list containing an arbitrary number of elements.
     * See <a href="#unmodifiable">Unmodifiable Lists</a> for details.
     *
     * @apiNote
     * This method also accepts a single array as an argument. The element type of
     * the resulting list will be the component type of the array, and the size of
     * the list will be equal to the length of the array. To create a list with
     * a single element that is an array, do the following:
     *
     * <pre>{@code
     *     String[] array = ... ;
     *     List<String[]> list = List.<String[]>of(array);
     * }</pre>
     *
     * This will cause the {@link List#of(Object) List.of(E)} method
     * to be invoked instead.
     *
     * @param <E> the {@code List}'s element type
     * @param elements the elements to be contained in the list
     * @return a {@code List} containing the specified elements
     * @throws NullPointerException if an element is {@code null} or if the array is {@code null}
     *
     * @since 9
     */
    @SafeVarargs
    @SuppressWarnings("varargs")
    static <E> List<E> of(E... elements) {
        switch (elements.length) { // implicit null check of elements
            case 0:
                return ImmutableCollections.emptyList();
            case 1:
                return new ImmutableCollections.List12<>(elements[0]);
            case 2:
                return new ImmutableCollections.List12<>(elements[0], elements[1]);
            default:
                return new ImmutableCollections.ListN<>(elements);
        }
    }

    
Returns an unmodifiable List containing the elements of
the given Collection, in its iteration order. The given Collection must not be null,
and it must not contain any null elements. If the given Collection is subsequently
modified, the returned List will not reflect such modifications.
Params:
coll – a Collection from which elements are drawn, must be non-null
Type parameters:
<E> – the List's element type
Throws:
NullPointerException – if coll is null, or if it contains any nulls
Implementation Note:

If the given Collection is an unmodifiable List,
calling copyOf will generally not create a copy.
Returns:
a List containing the elements of the given Collection
Since:
10/**
     * Returns an <a href="#unmodifiable">unmodifiable List</a> containing the elements of
     * the given Collection, in its iteration order. The given Collection must not be null,
     * and it must not contain any null elements. If the given Collection is subsequently
     * modified, the returned List will not reflect such modifications.
     *
     * @implNote
     * If the given Collection is an <a href="#unmodifiable">unmodifiable List</a>,
     * calling copyOf will generally not create a copy.
     *
     * @param <E> the {@code List}'s element type
     * @param coll a {@code Collection} from which elements are drawn, must be non-null
     * @return a {@code List} containing the elements of the given {@code Collection}
     * @throws NullPointerException if coll is null, or if it contains any nulls
     * @since 10
     */
    static <E> List<E> copyOf(Collection<? extends E> coll) {
        return ImmutableCollections.listCopy(coll);
    }
}