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. 
class com.google.common.collect.Collections2$TransformedCollection<F, T> extends java.util.AbstractCollection<T>
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.google.common.collect.Collections2$TransformedCollection
  super_class: java.util.AbstractCollection
{
  final java.util.Collection<F> fromCollection;
    descriptor: Ljava/util/Collection;
    flags: (0x0010) ACC_FINAL
    Signature: Ljava/util/Collection<TF;>;

  final com.google.common.base.Function<? super F, ? extends T> function;
    descriptor: Lcom/google/common/base/Function;
    flags: (0x0010) ACC_FINAL
    Signature: Lcom/google/common/base/Function<-TF;+TT;>;

  void <init>(java.util.Collection<F>, com.google.common.base.Function<? super F, ? extends T>);
    descriptor: (Ljava/util/Collection;Lcom/google/common/base/Function;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=3, args_size=3
        start local 0 // com.google.common.collect.Collections2$TransformedCollection this
        start local 1 // java.util.Collection fromCollection
        start local 2 // com.google.common.base.Function function
         0: .line 268
            aload 0 /* this */
            invokespecial java.util.AbstractCollection.<init>:()V
         1: .line 269
            aload 0 /* this */
            aload 1 /* fromCollection */
            invokestatic com.google.common.base.Preconditions.checkNotNull:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast java.util.Collection
            putfield com.google.common.collect.Collections2$TransformedCollection.fromCollection:Ljava/util/Collection;
         2: .line 270
            aload 0 /* this */
            aload 2 /* function */
            invokestatic com.google.common.base.Preconditions.checkNotNull:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast com.google.common.base.Function
            putfield com.google.common.collect.Collections2$TransformedCollection.function:Lcom/google/common/base/Function;
         3: .line 271
            return
        end local 2 // com.google.common.base.Function function
        end local 1 // java.util.Collection fromCollection
        end local 0 // com.google.common.collect.Collections2$TransformedCollection this
      LocalVariableTable:
        Start  End  Slot            Name  Signature
            0    4     0            this  Lcom/google/common/collect/Collections2$TransformedCollection<TF;TT;>;
            0    4     1  fromCollection  Ljava/util/Collection<TF;>;
            0    4     2        function  Lcom/google/common/base/Function<-TF;+TT;>;
    Signature: (Ljava/util/Collection<TF;>;Lcom/google/common/base/Function<-TF;+TT;>;)V
    MethodParameters:
                Name  Flags
      fromCollection  
      function        

  public void clear();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.google.common.collect.Collections2$TransformedCollection this
         0: .line 275
            aload 0 /* this */
            getfield com.google.common.collect.Collections2$TransformedCollection.fromCollection:Ljava/util/Collection;
            invokeinterface java.util.Collection.clear:()V
         1: .line 276
            return
        end local 0 // com.google.common.collect.Collections2$TransformedCollection this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lcom/google/common/collect/Collections2$TransformedCollection<TF;TT;>;

  public boolean isEmpty();
    descriptor: ()Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.google.common.collect.Collections2$TransformedCollection this
         0: .line 280
            aload 0 /* this */
            getfield com.google.common.collect.Collections2$TransformedCollection.fromCollection:Ljava/util/Collection;
            invokeinterface java.util.Collection.isEmpty:()Z
            ireturn
        end local 0 // com.google.common.collect.Collections2$TransformedCollection this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/collect/Collections2$TransformedCollection<TF;TT;>;

  public java.util.Iterator<T> iterator();
    descriptor: ()Ljava/util/Iterator;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // com.google.common.collect.Collections2$TransformedCollection this
         0: .line 285
            aload 0 /* this */
            getfield com.google.common.collect.Collections2$TransformedCollection.fromCollection:Ljava/util/Collection;
            invokeinterface java.util.Collection.iterator:()Ljava/util/Iterator;
            aload 0 /* this */
            getfield com.google.common.collect.Collections2$TransformedCollection.function:Lcom/google/common/base/Function;
            invokestatic com.google.common.collect.Iterators.transform:(Ljava/util/Iterator;Lcom/google/common/base/Function;)Ljava/util/Iterator;
            areturn
        end local 0 // com.google.common.collect.Collections2$TransformedCollection this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/collect/Collections2$TransformedCollection<TF;TT;>;
    Signature: ()Ljava/util/Iterator<TT;>;

  public java.util.Spliterator<T> spliterator();
    descriptor: ()Ljava/util/Spliterator;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // com.google.common.collect.Collections2$TransformedCollection this
         0: .line 290
            aload 0 /* this */
            getfield com.google.common.collect.Collections2$TransformedCollection.fromCollection:Ljava/util/Collection;
            invokeinterface java.util.Collection.spliterator:()Ljava/util/Spliterator;
            aload 0 /* this */
            getfield com.google.common.collect.Collections2$TransformedCollection.function:Lcom/google/common/base/Function;
            invokestatic com.google.common.collect.CollectSpliterators.map:(Ljava/util/Spliterator;Ljava/util/function/Function;)Ljava/util/Spliterator;
            areturn
        end local 0 // com.google.common.collect.Collections2$TransformedCollection this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/collect/Collections2$TransformedCollection<TF;TT;>;
    Signature: ()Ljava/util/Spliterator<TT;>;

  public void forEach(java.util.function.Consumer<? super T>);
    descriptor: (Ljava/util/function/Consumer;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // com.google.common.collect.Collections2$TransformedCollection this
        start local 1 // java.util.function.Consumer action
         0: .line 295
            aload 1 /* action */
            invokestatic com.google.common.base.Preconditions.checkNotNull:(Ljava/lang/Object;)Ljava/lang/Object;
            pop
         1: .line 296
            aload 0 /* this */
            getfield com.google.common.collect.Collections2$TransformedCollection.fromCollection:Ljava/util/Collection;
            aload 0 /* this */
            aload 1 /* action */
            invokedynamic accept(Lcom/google/common/collect/Collections2$TransformedCollection;Ljava/util/function/Consumer;)Ljava/util/function/Consumer;
              Bootstrap: invokestatic java.lang.invoke.LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
                Method arguments:
                  (Ljava/lang/Object;)V
                  com/google/common/collect/Collections2$TransformedCollection.lambda$0(Ljava/util/function/Consumer;Ljava/lang/Object;)V (7)
                  (Ljava/lang/Object;)V
            invokeinterface java.util.Collection.forEach:(Ljava/util/function/Consumer;)V
         2: .line 297
            return
        end local 1 // java.util.function.Consumer action
        end local 0 // com.google.common.collect.Collections2$TransformedCollection this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    3     0    this  Lcom/google/common/collect/Collections2$TransformedCollection<TF;TT;>;
            0    3     1  action  Ljava/util/function/Consumer<-TT;>;
    Signature: (Ljava/util/function/Consumer<-TT;>;)V
    MethodParameters:
        Name  Flags
      action  

  public boolean removeIf(java.util.function.Predicate<? super T>);
    descriptor: (Ljava/util/function/Predicate;)Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // com.google.common.collect.Collections2$TransformedCollection this
        start local 1 // java.util.function.Predicate filter
         0: .line 301
            aload 1 /* filter */
            invokestatic com.google.common.base.Preconditions.checkNotNull:(Ljava/lang/Object;)Ljava/lang/Object;
            pop
         1: .line 302
            aload 0 /* this */
            getfield com.google.common.collect.Collections2$TransformedCollection.fromCollection:Ljava/util/Collection;
            aload 0 /* this */
            aload 1 /* filter */
            invokedynamic test(Lcom/google/common/collect/Collections2$TransformedCollection;Ljava/util/function/Predicate;)Ljava/util/function/Predicate;
              Bootstrap: invokestatic java.lang.invoke.LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
                Method arguments:
                  (Ljava/lang/Object;)Z
                  com/google/common/collect/Collections2$TransformedCollection.lambda$1(Ljava/util/function/Predicate;Ljava/lang/Object;)Z (7)
                  (Ljava/lang/Object;)Z
            invokeinterface java.util.Collection.removeIf:(Ljava/util/function/Predicate;)Z
            ireturn
        end local 1 // java.util.function.Predicate filter
        end local 0 // com.google.common.collect.Collections2$TransformedCollection this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    2     0    this  Lcom/google/common/collect/Collections2$TransformedCollection<TF;TT;>;
            0    2     1  filter  Ljava/util/function/Predicate<-TT;>;
    Signature: (Ljava/util/function/Predicate<-TT;>;)Z
    MethodParameters:
        Name  Flags
      filter  

  public int size();
    descriptor: ()I
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.google.common.collect.Collections2$TransformedCollection this
         0: .line 307
            aload 0 /* this */
            getfield com.google.common.collect.Collections2$TransformedCollection.fromCollection:Ljava/util/Collection;
            invokeinterface java.util.Collection.size:()I
            ireturn
        end local 0 // com.google.common.collect.Collections2$TransformedCollection this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/collect/Collections2$TransformedCollection<TF;TT;>;

  private void lambda$0(java.util.function.Consumer, java.lang.Object);
    descriptor: (Ljava/util/function/Consumer;Ljava/lang/Object;)V
    flags: (0x1002) ACC_PRIVATE, ACC_SYNTHETIC
    Code:
      stack=3, locals=3, args_size=3
        start local 0 // com.google.common.collect.Collections2$TransformedCollection this
        start local 2 // java.lang.Object f
         0: .line 296
            aload 1
            aload 0 /* this */
            getfield com.google.common.collect.Collections2$TransformedCollection.function:Lcom/google/common/base/Function;
            aload 2 /* f */
            invokeinterface com.google.common.base.Function.apply:(Ljava/lang/Object;)Ljava/lang/Object;
            invokeinterface java.util.function.Consumer.accept:(Ljava/lang/Object;)V
            return
        end local 2 // java.lang.Object f
        end local 0 // com.google.common.collect.Collections2$TransformedCollection this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/collect/Collections2$TransformedCollection<TF;TT;>;
            0    1     2     f  TF;

  private boolean lambda$1(java.util.function.Predicate, java.lang.Object);
    descriptor: (Ljava/util/function/Predicate;Ljava/lang/Object;)Z
    flags: (0x1002) ACC_PRIVATE, ACC_SYNTHETIC
    Code:
      stack=3, locals=3, args_size=3
        start local 0 // com.google.common.collect.Collections2$TransformedCollection this
        start local 2 // java.lang.Object element
         0: .line 302
            aload 1
            aload 0 /* this */
            getfield com.google.common.collect.Collections2$TransformedCollection.function:Lcom/google/common/base/Function;
            aload 2 /* element */
            invokeinterface com.google.common.base.Function.apply:(Ljava/lang/Object;)Ljava/lang/Object;
            invokeinterface java.util.function.Predicate.test:(Ljava/lang/Object;)Z
            ireturn
        end local 2 // java.lang.Object element
        end local 0 // com.google.common.collect.Collections2$TransformedCollection this
      LocalVariableTable:
        Start  End  Slot     Name  Signature
            0    1     0     this  Lcom/google/common/collect/Collections2$TransformedCollection<TF;TT;>;
            0    1     2  element  TF;
}
Signature: <F:Ljava/lang/Object;T:Ljava/lang/Object;>Ljava/util/AbstractCollection<TT;>;
SourceFile: "Collections2.java"
NestHost: com.google.common.collect.Collections2
InnerClasses:
  TransformedCollection = com.google.common.collect.Collections2$TransformedCollection of com.google.common.collect.Collections2
  public final Lookup = java.lang.invoke.MethodHandles$Lookup of java.lang.invoke.MethodHandles