https://github.com/eclipse/eclipse-collections/eclipse-collections: Eclipse Collections is a collections framework for Java. It has JDK-compatible List, Set and Map implementations with a rich API and set of utility classes that work with any JDK compatible Collections, Arrays, Maps or Strings. The iteration protocol was inspired by the Smalltalk collection framework.
  • Craig P. Motlin
  • Donald Raab
  • Mohammad A. Rezaei
  • Hiroshi Ito
  • Nikhil J. Nanivadekar 
public final class org.eclipse.collections.impl.lazy.iterator.DistinctIterator<T> implements java.util.Iterator<T>
  minor version: 0
  major version: 59
  flags: flags: (0x0031) ACC_PUBLIC, ACC_FINAL, ACC_SUPER
  this_class: org.eclipse.collections.impl.lazy.iterator.DistinctIterator
  super_class: java.lang.Object
{
  private static final java.lang.Object NULL;
    descriptor: Ljava/lang/Object;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL

  private final java.util.Iterator<T> iterator;
    descriptor: Ljava/util/Iterator;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Ljava/util/Iterator<TT;>;

  private final org.eclipse.collections.api.set.MutableSet<T> seenSoFar;
    descriptor: Lorg/eclipse/collections/api/set/MutableSet;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Lorg/eclipse/collections/api/set/MutableSet<TT;>;

  private java.lang.Object next;
    descriptor: Ljava/lang/Object;
    flags: (0x0002) ACC_PRIVATE

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=2, locals=0, args_size=0
         0: .line 22
            new java.lang.Object
            dup
            invokespecial java.lang.Object.<init>:()V
            putstatic org.eclipse.collections.impl.lazy.iterator.DistinctIterator.NULL:Ljava/lang/Object;
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  public void <init>(java.lang.Iterable<T>);
    descriptor: (Ljava/lang/Iterable;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // org.eclipse.collections.impl.lazy.iterator.DistinctIterator this
        start local 1 // java.lang.Iterable iterable
         0: .line 29
            aload 0 /* this */
            aload 1 /* iterable */
            invokeinterface java.lang.Iterable.iterator:()Ljava/util/Iterator;
            invokespecial org.eclipse.collections.impl.lazy.iterator.DistinctIterator.<init>:(Ljava/util/Iterator;)V
         1: .line 30
            return
        end local 1 // java.lang.Iterable iterable
        end local 0 // org.eclipse.collections.impl.lazy.iterator.DistinctIterator this
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            0    2     0      this  Lorg/eclipse/collections/impl/lazy/iterator/DistinctIterator<TT;>;
            0    2     1  iterable  Ljava/lang/Iterable<TT;>;
    Signature: (Ljava/lang/Iterable<TT;>;)V
    MethodParameters:
          Name  Flags
      iterable  

  public void <init>(java.util.Iterator<T>);
    descriptor: (Ljava/util/Iterator;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // org.eclipse.collections.impl.lazy.iterator.DistinctIterator this
        start local 1 // java.util.Iterator iterator
         0: .line 32
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 24
            aload 0 /* this */
            invokestatic org.eclipse.collections.impl.set.mutable.UnifiedSet.newSet:()Lorg/eclipse/collections/impl/set/mutable/UnifiedSet;
            putfield org.eclipse.collections.impl.lazy.iterator.DistinctIterator.seenSoFar:Lorg/eclipse/collections/api/set/MutableSet;
         2: .line 25
            aload 0 /* this */
            getstatic org.eclipse.collections.impl.lazy.iterator.DistinctIterator.NULL:Ljava/lang/Object;
            putfield org.eclipse.collections.impl.lazy.iterator.DistinctIterator.next:Ljava/lang/Object;
         3: .line 34
            aload 0 /* this */
            aload 1 /* iterator */
            putfield org.eclipse.collections.impl.lazy.iterator.DistinctIterator.iterator:Ljava/util/Iterator;
         4: .line 35
            return
        end local 1 // java.util.Iterator iterator
        end local 0 // org.eclipse.collections.impl.lazy.iterator.DistinctIterator this
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            0    5     0      this  Lorg/eclipse/collections/impl/lazy/iterator/DistinctIterator<TT;>;
            0    5     1  iterator  Ljava/util/Iterator<TT;>;
    Signature: (Ljava/util/Iterator<TT;>;)V
    MethodParameters:
          Name  Flags
      iterator  

  public void remove();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // org.eclipse.collections.impl.lazy.iterator.DistinctIterator this
         0: .line 40
            new java.lang.UnsupportedOperationException
            dup
            ldc "Cannot remove from a distinct iterator"
            invokespecial java.lang.UnsupportedOperationException.<init>:(Ljava/lang/String;)V
            athrow
        end local 0 // org.eclipse.collections.impl.lazy.iterator.DistinctIterator this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/eclipse/collections/impl/lazy/iterator/DistinctIterator<TT;>;

  public boolean hasNext();
    descriptor: ()Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=1
        start local 0 // org.eclipse.collections.impl.lazy.iterator.DistinctIterator this
         0: .line 46
            aload 0 /* this */
            getfield org.eclipse.collections.impl.lazy.iterator.DistinctIterator.next:Ljava/lang/Object;
            getstatic org.eclipse.collections.impl.lazy.iterator.DistinctIterator.NULL:Ljava/lang/Object;
            if_acmpeq 6
         1: .line 48
            iconst_1
            ireturn
         2: .line 52
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield org.eclipse.collections.impl.lazy.iterator.DistinctIterator.iterator:Ljava/util/Iterator;
            invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
            astore 1 /* temp */
        start local 1 // java.lang.Object temp
         3: .line 53
            aload 0 /* this */
            getfield org.eclipse.collections.impl.lazy.iterator.DistinctIterator.seenSoFar:Lorg/eclipse/collections/api/set/MutableSet;
            aload 1 /* temp */
            invokeinterface org.eclipse.collections.api.set.MutableSet.add:(Ljava/lang/Object;)Z
            ifeq 6
         4: .line 55
            aload 0 /* this */
            aload 1 /* temp */
            putfield org.eclipse.collections.impl.lazy.iterator.DistinctIterator.next:Ljava/lang/Object;
         5: .line 56
            iconst_1
            ireturn
        end local 1 // java.lang.Object temp
         6: .line 50
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield org.eclipse.collections.impl.lazy.iterator.DistinctIterator.iterator:Ljava/util/Iterator;
            invokeinterface java.util.Iterator.hasNext:()Z
            ifne 2
         7: .line 59
            iconst_0
            ireturn
        end local 0 // org.eclipse.collections.impl.lazy.iterator.DistinctIterator this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    8     0  this  Lorg/eclipse/collections/impl/lazy/iterator/DistinctIterator<TT;>;
            3    6     1  temp  TT;

  public T next();
    descriptor: ()Ljava/lang/Object;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=1
        start local 0 // org.eclipse.collections.impl.lazy.iterator.DistinctIterator this
         0: .line 65
            aload 0 /* this */
            getfield org.eclipse.collections.impl.lazy.iterator.DistinctIterator.next:Ljava/lang/Object;
            getstatic org.eclipse.collections.impl.lazy.iterator.DistinctIterator.NULL:Ljava/lang/Object;
            if_acmpne 1
            aload 0 /* this */
            invokevirtual org.eclipse.collections.impl.lazy.iterator.DistinctIterator.hasNext:()Z
            ifeq 4
         1: .line 67
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield org.eclipse.collections.impl.lazy.iterator.DistinctIterator.next:Ljava/lang/Object;
            astore 1 /* temp */
        start local 1 // java.lang.Object temp
         2: .line 68
            aload 0 /* this */
            getstatic org.eclipse.collections.impl.lazy.iterator.DistinctIterator.NULL:Ljava/lang/Object;
            putfield org.eclipse.collections.impl.lazy.iterator.DistinctIterator.next:Ljava/lang/Object;
         3: .line 69
            aload 1 /* temp */
            areturn
        end local 1 // java.lang.Object temp
         4: .line 71
      StackMap locals:
      StackMap stack:
            new java.util.NoSuchElementException
            dup
            invokespecial java.util.NoSuchElementException.<init>:()V
            athrow
        end local 0 // org.eclipse.collections.impl.lazy.iterator.DistinctIterator this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    5     0  this  Lorg/eclipse/collections/impl/lazy/iterator/DistinctIterator<TT;>;
            2    4     1  temp  Ljava/lang/Object;
    Signature: ()TT;
}
Signature: <T:Ljava/lang/Object;>Ljava/lang/Object;Ljava/util/Iterator<TT;>;
SourceFile: "DistinctIterator.java"