https://github.com/google/guava/guava: Guava is a suite of core and expanded libraries that include utility classes, google's collections, io classes, and much much more. 
public final class com.google.common.collect.Collections2
  minor version: 0
  major version: 59
  flags: flags: (0x0031) ACC_PUBLIC, ACC_FINAL, ACC_SUPER
  this_class: com.google.common.collect.Collections2
  super_class: java.lang.Object
{
  private void <init>();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.google.common.collect.Collections2 this
         0: .line 57
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // com.google.common.collect.Collections2 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/collect/Collections2;

  public static <E> java.util.Collection<E> filter(java.util.Collection<E>, com.google.common.base.Predicate<? super E>);
    descriptor: (Ljava/util/Collection;Lcom/google/common/base/Predicate;)Ljava/util/Collection;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=4, locals=2, args_size=2
        start local 0 // java.util.Collection unfiltered
        start local 1 // com.google.common.base.Predicate predicate
         0: .line 87
            aload 0 /* unfiltered */
            instanceof com.google.common.collect.Collections2$FilteredCollection
            ifeq 2
         1: .line 90
            aload 0 /* unfiltered */
            checkcast com.google.common.collect.Collections2$FilteredCollection
            aload 1 /* predicate */
            invokevirtual com.google.common.collect.Collections2$FilteredCollection.createCombined:(Lcom/google/common/base/Predicate;)Lcom/google/common/collect/Collections2$FilteredCollection;
            areturn
         2: .line 93
      StackMap locals:
      StackMap stack:
            new com.google.common.collect.Collections2$FilteredCollection
            dup
            aload 0 /* unfiltered */
            invokestatic com.google.common.base.Preconditions.checkNotNull:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast java.util.Collection
            aload 1 /* predicate */
            invokestatic com.google.common.base.Preconditions.checkNotNull:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast com.google.common.base.Predicate
            invokespecial com.google.common.collect.Collections2$FilteredCollection.<init>:(Ljava/util/Collection;Lcom/google/common/base/Predicate;)V
            areturn
        end local 1 // com.google.common.base.Predicate predicate
        end local 0 // java.util.Collection unfiltered
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0    3     0  unfiltered  Ljava/util/Collection<TE;>;
            0    3     1   predicate  Lcom/google/common/base/Predicate<-TE;>;
    Signature: <E:Ljava/lang/Object;>(Ljava/util/Collection<TE;>;Lcom/google/common/base/Predicate<-TE;>;)Ljava/util/Collection<TE;>;
    MethodParameters:
            Name  Flags
      unfiltered  
      predicate   

  static boolean safeContains(java.util.Collection<?>, );
    descriptor: (Ljava/util/Collection;Ljava/lang/Object;)Z
    flags: (0x0008) ACC_STATIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // java.util.Collection collection
        start local 1 // java.lang.Object object
         0: .line 101
            aload 0 /* collection */
            invokestatic com.google.common.base.Preconditions.checkNotNull:(Ljava/lang/Object;)Ljava/lang/Object;
            pop
         1: .line 103
            aload 0 /* collection */
            aload 1 /* object */
            invokeinterface java.util.Collection.contains:(Ljava/lang/Object;)Z
         2: ireturn
         3: .line 104
      StackMap locals:
      StackMap stack: java.lang.RuntimeException
            pop
         4: .line 105
            iconst_0
            ireturn
        end local 1 // java.lang.Object object
        end local 0 // java.util.Collection collection
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0    5     0  collection  Ljava/util/Collection<*>;
            0    5     1      object  Ljava/lang/Object;
      Exception table:
        from    to  target  type
           1     2       3  Class java.lang.ClassCastException
           1     2       3  Class java.lang.NullPointerException
    Signature: (Ljava/util/Collection<*>;Ljava/lang/Object;)Z
    RuntimeVisibleTypeAnnotations: 
      METHOD_FORMAL_PARAMETER
        org.checkerframework.checker.nullness.qual.Nullable()
    MethodParameters:
            Name  Flags
      collection  
      object      

  static boolean safeRemove(java.util.Collection<?>, );
    descriptor: (Ljava/util/Collection;Ljava/lang/Object;)Z
    flags: (0x0008) ACC_STATIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // java.util.Collection collection
        start local 1 // java.lang.Object object
         0: .line 114
            aload 0 /* collection */
            invokestatic com.google.common.base.Preconditions.checkNotNull:(Ljava/lang/Object;)Ljava/lang/Object;
            pop
         1: .line 116
            aload 0 /* collection */
            aload 1 /* object */
            invokeinterface java.util.Collection.remove:(Ljava/lang/Object;)Z
         2: ireturn
         3: .line 117
      StackMap locals:
      StackMap stack: java.lang.RuntimeException
            pop
         4: .line 118
            iconst_0
            ireturn
        end local 1 // java.lang.Object object
        end local 0 // java.util.Collection collection
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0    5     0  collection  Ljava/util/Collection<*>;
            0    5     1      object  Ljava/lang/Object;
      Exception table:
        from    to  target  type
           1     2       3  Class java.lang.ClassCastException
           1     2       3  Class java.lang.NullPointerException
    Signature: (Ljava/util/Collection<*>;Ljava/lang/Object;)Z
    RuntimeVisibleTypeAnnotations: 
      METHOD_FORMAL_PARAMETER
        org.checkerframework.checker.nullness.qual.Nullable()
    MethodParameters:
            Name  Flags
      collection  
      object      

  public static <F, T> java.util.Collection<T> transform(java.util.Collection<F>, com.google.common.base.Function<? super F, T>);
    descriptor: (Ljava/util/Collection;Lcom/google/common/base/Function;)Ljava/util/Collection;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=4, locals=2, args_size=2
        start local 0 // java.util.Collection fromCollection
        start local 1 // com.google.common.base.Function function
         0: .line 261
            new com.google.common.collect.Collections2$TransformedCollection
            dup
            aload 0 /* fromCollection */
            aload 1 /* function */
            invokespecial com.google.common.collect.Collections2$TransformedCollection.<init>:(Ljava/util/Collection;Lcom/google/common/base/Function;)V
            areturn
        end local 1 // com.google.common.base.Function function
        end local 0 // java.util.Collection fromCollection
      LocalVariableTable:
        Start  End  Slot            Name  Signature
            0    1     0  fromCollection  Ljava/util/Collection<TF;>;
            0    1     1        function  Lcom/google/common/base/Function<-TF;TT;>;
    Signature: <F:Ljava/lang/Object;T:Ljava/lang/Object;>(Ljava/util/Collection<TF;>;Lcom/google/common/base/Function<-TF;TT;>;)Ljava/util/Collection<TT;>;
    MethodParameters:
                Name  Flags
      fromCollection  
      function        

  static boolean containsAllImpl(java.util.Collection<?>, java.util.Collection<?>);
    descriptor: (Ljava/util/Collection;Ljava/util/Collection;)Z
    flags: (0x0008) ACC_STATIC
    Code:
      stack=2, locals=4, args_size=2
        start local 0 // java.util.Collection self
        start local 1 // java.util.Collection c
         0: .line 323
            aload 1 /* c */
            invokeinterface java.util.Collection.iterator:()Ljava/util/Iterator;
            astore 3
            goto 4
      StackMap locals: java.util.Collection java.util.Collection top java.util.Iterator
      StackMap stack:
         1: aload 3
            invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
            astore 2 /* o */
        start local 2 // java.lang.Object o
         2: .line 324
            aload 0 /* self */
            aload 2 /* o */
            invokeinterface java.util.Collection.contains:(Ljava/lang/Object;)Z
            ifne 4
         3: .line 325
            iconst_0
            ireturn
        end local 2 // java.lang.Object o
         4: .line 323
      StackMap locals:
      StackMap stack:
            aload 3
            invokeinterface java.util.Iterator.hasNext:()Z
            ifne 1
         5: .line 328
            iconst_1
            ireturn
        end local 1 // java.util.Collection c
        end local 0 // java.util.Collection self
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    6     0  self  Ljava/util/Collection<*>;
            0    6     1     c  Ljava/util/Collection<*>;
            2    4     2     o  Ljava/lang/Object;
    Signature: (Ljava/util/Collection<*>;Ljava/util/Collection<*>;)Z
    MethodParameters:
      Name  Flags
      self  
      c     

  static java.lang.String toStringImpl(java.util.Collection<?>);
    descriptor: (Ljava/util/Collection;)Ljava/lang/String;
    flags: (0x0008) ACC_STATIC
    Code:
      stack=2, locals=5, args_size=1
        start local 0 // java.util.Collection collection
         0: .line 333
            aload 0 /* collection */
            invokeinterface java.util.Collection.size:()I
            invokestatic com.google.common.collect.Collections2.newStringBuilderForCollection:(I)Ljava/lang/StringBuilder;
            bipush 91
            invokevirtual java.lang.StringBuilder.append:(C)Ljava/lang/StringBuilder;
            astore 1 /* sb */
        start local 1 // java.lang.StringBuilder sb
         1: .line 334
            iconst_1
            istore 2 /* first */
        start local 2 // boolean first
         2: .line 335
            aload 0 /* collection */
            invokeinterface java.util.Collection.iterator:()Ljava/util/Iterator;
            astore 4
            goto 11
      StackMap locals: java.util.Collection java.lang.StringBuilder int top java.util.Iterator
      StackMap stack:
         3: aload 4
            invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
            astore 3 /* o */
        start local 3 // java.lang.Object o
         4: .line 336
            iload 2 /* first */
            ifne 6
         5: .line 337
            aload 1 /* sb */
            ldc ", "
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
         6: .line 339
      StackMap locals: java.util.Collection java.lang.StringBuilder int java.lang.Object java.util.Iterator
      StackMap stack:
            iconst_0
            istore 2 /* first */
         7: .line 340
            aload 3 /* o */
            aload 0 /* collection */
            if_acmpne 10
         8: .line 341
            aload 1 /* sb */
            ldc "(this Collection)"
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
         9: .line 342
            goto 11
        10: .line 343
      StackMap locals:
      StackMap stack:
            aload 1 /* sb */
            aload 3 /* o */
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/Object;)Ljava/lang/StringBuilder;
            pop
        end local 3 // java.lang.Object o
        11: .line 335
      StackMap locals: java.util.Collection java.lang.StringBuilder int top java.util.Iterator
      StackMap stack:
            aload 4
            invokeinterface java.util.Iterator.hasNext:()Z
            ifne 3
        12: .line 346
            aload 1 /* sb */
            bipush 93
            invokevirtual java.lang.StringBuilder.append:(C)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            areturn
        end local 2 // boolean first
        end local 1 // java.lang.StringBuilder sb
        end local 0 // java.util.Collection collection
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0   13     0  collection  Ljava/util/Collection<*>;
            1   13     1          sb  Ljava/lang/StringBuilder;
            2   13     2       first  Z
            4   11     3           o  Ljava/lang/Object;
    Signature: (Ljava/util/Collection<*>;)Ljava/lang/String;
    MethodParameters:
            Name  Flags
      collection  final

  static java.lang.StringBuilder newStringBuilderForCollection(int);
    descriptor: (I)Ljava/lang/StringBuilder;
    flags: (0x0008) ACC_STATIC
    Code:
      stack=6, locals=1, args_size=1
        start local 0 // int size
         0: .line 351
            iload 0 /* size */
            ldc "size"
            invokestatic com.google.common.collect.CollectPreconditions.checkNonnegative:(ILjava/lang/String;)I
            pop
         1: .line 352
            new java.lang.StringBuilder
            dup
            iload 0 /* size */
            i2l
            ldc 8
            lmul
            ldc 1073741824
            invokestatic java.lang.Math.min:(JJ)J
            l2i
            invokespecial java.lang.StringBuilder.<init>:(I)V
            areturn
        end local 0 // int size
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  size  I
    MethodParameters:
      Name  Flags
      size  

  public static <E extends java.lang.Comparable<? super E>> java.util.Collection<java.util.List<E>> orderedPermutations(java.lang.Iterable<E>);
    descriptor: (Ljava/lang/Iterable;)Ljava/util/Collection;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // java.lang.Iterable elements
         0: .line 380
            aload 0 /* elements */
            invokestatic com.google.common.collect.Ordering.natural:()Lcom/google/common/collect/Ordering;
            invokestatic com.google.common.collect.Collections2.orderedPermutations:(Ljava/lang/Iterable;Ljava/util/Comparator;)Ljava/util/Collection;
            areturn
        end local 0 // java.lang.Iterable elements
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            0    1     0  elements  Ljava/lang/Iterable<TE;>;
    Signature: <E::Ljava/lang/Comparable<-TE;>;>(Ljava/lang/Iterable<TE;>;)Ljava/util/Collection<Ljava/util/List<TE;>;>;
    RuntimeInvisibleAnnotations: 
      com.google.common.annotations.Beta()
    MethodParameters:
          Name  Flags
      elements  

  public static <E> java.util.Collection<java.util.List<E>> orderedPermutations(java.lang.Iterable<E>, java.util.Comparator<? super E>);
    descriptor: (Ljava/lang/Iterable;Ljava/util/Comparator;)Ljava/util/Collection;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=4, locals=2, args_size=2
        start local 0 // java.lang.Iterable elements
        start local 1 // java.util.Comparator comparator
         0: .line 432
            new com.google.common.collect.Collections2$OrderedPermutationCollection
            dup
            aload 0 /* elements */
            aload 1 /* comparator */
            invokespecial com.google.common.collect.Collections2$OrderedPermutationCollection.<init>:(Ljava/lang/Iterable;Ljava/util/Comparator;)V
            areturn
        end local 1 // java.util.Comparator comparator
        end local 0 // java.lang.Iterable elements
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0    1     0    elements  Ljava/lang/Iterable<TE;>;
            0    1     1  comparator  Ljava/util/Comparator<-TE;>;
    Signature: <E:Ljava/lang/Object;>(Ljava/lang/Iterable<TE;>;Ljava/util/Comparator<-TE;>;)Ljava/util/Collection<Ljava/util/List<TE;>;>;
    RuntimeInvisibleAnnotations: 
      com.google.common.annotations.Beta()
    MethodParameters:
            Name  Flags
      elements    
      comparator  

  public static <E> java.util.Collection<java.util.List<E>> permutations(java.util.Collection<E>);
    descriptor: (Ljava/util/Collection;)Ljava/util/Collection;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // java.util.Collection elements
         0: .line 577
            new com.google.common.collect.Collections2$PermutationCollection
            dup
            aload 0 /* elements */
            invokestatic com.google.common.collect.ImmutableList.copyOf:(Ljava/util/Collection;)Lcom/google/common/collect/ImmutableList;
            invokespecial com.google.common.collect.Collections2$PermutationCollection.<init>:(Lcom/google/common/collect/ImmutableList;)V
            areturn
        end local 0 // java.util.Collection elements
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            0    1     0  elements  Ljava/util/Collection<TE;>;
    Signature: <E:Ljava/lang/Object;>(Ljava/util/Collection<TE;>;)Ljava/util/Collection<Ljava/util/List<TE;>;>;
    RuntimeInvisibleAnnotations: 
      com.google.common.annotations.Beta()
    MethodParameters:
          Name  Flags
      elements  

  private static boolean isPermutation(java.util.List<?>, java.util.List<?>);
    descriptor: (Ljava/util/List;Ljava/util/List;)Z
    flags: (0x000a) ACC_PRIVATE, ACC_STATIC
    Code:
      stack=2, locals=4, args_size=2
        start local 0 // java.util.List first
        start local 1 // java.util.List second
         0: .line 682
            aload 0 /* first */
            invokeinterface java.util.List.size:()I
            aload 1 /* second */
            invokeinterface java.util.List.size:()I
            if_icmpeq 2
         1: .line 683
            iconst_0
            ireturn
         2: .line 685
      StackMap locals:
      StackMap stack:
            aload 0 /* first */
            invokestatic com.google.common.collect.HashMultiset.create:(Ljava/lang/Iterable;)Lcom/google/common/collect/HashMultiset;
            astore 2 /* firstMultiset */
        start local 2 // com.google.common.collect.Multiset firstMultiset
         3: .line 686
            aload 1 /* second */
            invokestatic com.google.common.collect.HashMultiset.create:(Ljava/lang/Iterable;)Lcom/google/common/collect/HashMultiset;
            astore 3 /* secondMultiset */
        start local 3 // com.google.common.collect.Multiset secondMultiset
         4: .line 687
            aload 2 /* firstMultiset */
            aload 3 /* secondMultiset */
            invokeinterface com.google.common.collect.Multiset.equals:(Ljava/lang/Object;)Z
            ireturn
        end local 3 // com.google.common.collect.Multiset secondMultiset
        end local 2 // com.google.common.collect.Multiset firstMultiset
        end local 1 // java.util.List second
        end local 0 // java.util.List first
      LocalVariableTable:
        Start  End  Slot            Name  Signature
            0    5     0           first  Ljava/util/List<*>;
            0    5     1          second  Ljava/util/List<*>;
            3    5     2   firstMultiset  Lcom/google/common/collect/Multiset<*>;
            4    5     3  secondMultiset  Lcom/google/common/collect/Multiset<*>;
    Signature: (Ljava/util/List<*>;Ljava/util/List<*>;)Z
    MethodParameters:
        Name  Flags
      first   
      second  
}
SourceFile: "Collections2.java"
NestMembers:
  com.google.common.collect.Collections2$FilteredCollection  com.google.common.collect.Collections2$OrderedPermutationCollection  com.google.common.collect.Collections2$OrderedPermutationIterator  com.google.common.collect.Collections2$PermutationCollection  com.google.common.collect.Collections2$PermutationIterator  com.google.common.collect.Collections2$TransformedCollection
InnerClasses:
  FilteredCollection = com.google.common.collect.Collections2$FilteredCollection of com.google.common.collect.Collections2
  private final OrderedPermutationCollection = com.google.common.collect.Collections2$OrderedPermutationCollection of com.google.common.collect.Collections2
  private final OrderedPermutationIterator = com.google.common.collect.Collections2$OrderedPermutationIterator of com.google.common.collect.Collections2
  private final PermutationCollection = com.google.common.collect.Collections2$PermutationCollection of com.google.common.collect.Collections2
  private PermutationIterator = com.google.common.collect.Collections2$PermutationIterator of com.google.common.collect.Collections2
  TransformedCollection = com.google.common.collect.Collections2$TransformedCollection of com.google.common.collect.Collections2
    RuntimeInvisibleAnnotations: 
      com.google.common.annotations.GwtCompatible()