public class java.util.concurrent.ConcurrentHashMap$KeySetView<K, V> extends java.util.concurrent.ConcurrentHashMap$CollectionView<K, V, K> implements java.util.Set<K>, java.io.Serializable
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: java.util.concurrent.ConcurrentHashMap$KeySetView
  super_class: java.util.concurrent.ConcurrentHashMap$CollectionView
{
  private static final long serialVersionUID;
    descriptor: J
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    ConstantValue: 7249069246763182397

  private final V value;
    descriptor: Ljava/lang/Object;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: TV;

  void <init>(java.util.concurrent.ConcurrentHashMap<K, V>, );
    descriptor: (Ljava/util/concurrent/ConcurrentHashMap;Ljava/lang/Object;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=3, args_size=3
        start local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
        start local 1 // java.util.concurrent.ConcurrentHashMap map
        start local 2 // java.lang.Object value
         0: .line 4590
            aload 0 /* this */
            aload 1 /* map */
            invokespecial java.util.concurrent.ConcurrentHashMap$CollectionView.<init>:(Ljava/util/concurrent/ConcurrentHashMap;)V
         1: .line 4591
            aload 0 /* this */
            aload 2 /* value */
            putfield java.util.concurrent.ConcurrentHashMap$KeySetView.value:Ljava/lang/Object;
         2: .line 4592
            return
        end local 2 // java.lang.Object value
        end local 1 // java.util.concurrent.ConcurrentHashMap map
        end local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    3     0   this  Ljava/util/concurrent/ConcurrentHashMap$KeySetView<TK;TV;>;
            0    3     1    map  Ljava/util/concurrent/ConcurrentHashMap<TK;TV;>;
            0    3     2  value  TV;
    Signature: (Ljava/util/concurrent/ConcurrentHashMap<TK;TV;>;TV;)V
    MethodParameters:
       Name  Flags
      map    
      value  

  public V getMappedValue();
    descriptor: ()Ljava/lang/Object;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
         0: .line 4601
            aload 0 /* this */
            getfield java.util.concurrent.ConcurrentHashMap$KeySetView.value:Ljava/lang/Object;
            areturn
        end local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Ljava/util/concurrent/ConcurrentHashMap$KeySetView<TK;TV;>;
    Signature: ()TV;

  public boolean contains(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
        start local 1 // java.lang.Object o
         0: .line 4607
            aload 0 /* this */
            getfield java.util.concurrent.ConcurrentHashMap$KeySetView.map:Ljava/util/concurrent/ConcurrentHashMap;
            aload 1 /* o */
            invokevirtual java.util.concurrent.ConcurrentHashMap.containsKey:(Ljava/lang/Object;)Z
            ireturn
        end local 1 // java.lang.Object o
        end local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Ljava/util/concurrent/ConcurrentHashMap$KeySetView<TK;TV;>;
            0    1     1     o  Ljava/lang/Object;
    MethodParameters:
      Name  Flags
      o     

  public boolean remove(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
        start local 1 // java.lang.Object o
         0: .line 4618
            aload 0 /* this */
            getfield java.util.concurrent.ConcurrentHashMap$KeySetView.map:Ljava/util/concurrent/ConcurrentHashMap;
            aload 1 /* o */
            invokevirtual java.util.concurrent.ConcurrentHashMap.remove:(Ljava/lang/Object;)Ljava/lang/Object;
            ifnull 1
            iconst_1
            ireturn
      StackMap locals:
      StackMap stack:
         1: iconst_0
            ireturn
        end local 1 // java.lang.Object o
        end local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Ljava/util/concurrent/ConcurrentHashMap$KeySetView<TK;TV;>;
            0    2     1     o  Ljava/lang/Object;
    MethodParameters:
      Name  Flags
      o     

  public java.util.Iterator<K> iterator();
    descriptor: ()Ljava/util/Iterator;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=7, locals=4, args_size=1
        start local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
         0: .line 4625
            aload 0 /* this */
            getfield java.util.concurrent.ConcurrentHashMap$KeySetView.map:Ljava/util/concurrent/ConcurrentHashMap;
            astore 2 /* m */
        start local 2 // java.util.concurrent.ConcurrentHashMap m
         1: .line 4626
            aload 2 /* m */
            getfield java.util.concurrent.ConcurrentHashMap.table:[Ljava/util/concurrent/ConcurrentHashMap$Node;
            dup
            astore 1 /* t */
        start local 1 // java.util.concurrent.ConcurrentHashMap$Node[] t
         2: ifnonnull 3
            iconst_0
            goto 4
      StackMap locals: java.util.concurrent.ConcurrentHashMap$Node[] java.util.concurrent.ConcurrentHashMap
      StackMap stack:
         3: aload 1 /* t */
            arraylength
      StackMap locals:
      StackMap stack: int
         4: istore 3 /* f */
        start local 3 // int f
         5: .line 4627
            new java.util.concurrent.ConcurrentHashMap$KeyIterator
            dup
            aload 1 /* t */
            iload 3 /* f */
            iconst_0
            iload 3 /* f */
            aload 2 /* m */
            invokespecial java.util.concurrent.ConcurrentHashMap$KeyIterator.<init>:([Ljava/util/concurrent/ConcurrentHashMap$Node;IIILjava/util/concurrent/ConcurrentHashMap;)V
            areturn
        end local 3 // int f
        end local 2 // java.util.concurrent.ConcurrentHashMap m
        end local 1 // java.util.concurrent.ConcurrentHashMap$Node[] t
        end local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    6     0  this  Ljava/util/concurrent/ConcurrentHashMap$KeySetView<TK;TV;>;
            2    6     1     t  [Ljava/util/concurrent/ConcurrentHashMap$Node;
            1    6     2     m  Ljava/util/concurrent/ConcurrentHashMap<TK;TV;>;
            5    6     3     f  I
    Signature: ()Ljava/util/Iterator<TK;>;

  public boolean add();
    descriptor: (Ljava/lang/Object;)Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=4, locals=3, args_size=2
        start local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
        start local 1 // java.lang.Object e
         0: .line 4642
            aload 0 /* this */
            getfield java.util.concurrent.ConcurrentHashMap$KeySetView.value:Ljava/lang/Object;
            dup
            astore 2 /* v */
        start local 2 // java.lang.Object v
         1: ifnonnull 3
         2: .line 4643
            new java.lang.UnsupportedOperationException
            dup
            invokespecial java.lang.UnsupportedOperationException.<init>:()V
            athrow
         3: .line 4644
      StackMap locals: java.lang.Object
      StackMap stack:
            aload 0 /* this */
            getfield java.util.concurrent.ConcurrentHashMap$KeySetView.map:Ljava/util/concurrent/ConcurrentHashMap;
            aload 1 /* e */
            aload 2 /* v */
            iconst_1
            invokevirtual java.util.concurrent.ConcurrentHashMap.putVal:(Ljava/lang/Object;Ljava/lang/Object;Z)Ljava/lang/Object;
            ifnonnull 4
            iconst_1
            ireturn
      StackMap locals:
      StackMap stack:
         4: iconst_0
            ireturn
        end local 2 // java.lang.Object v
        end local 1 // java.lang.Object e
        end local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    5     0  this  Ljava/util/concurrent/ConcurrentHashMap$KeySetView<TK;TV;>;
            0    5     1     e  TK;
            1    5     2     v  TV;
    Signature: (TK;)Z
    MethodParameters:
      Name  Flags
      e     

  public boolean addAll(java.util.Collection<? extends K>);
    descriptor: (Ljava/util/Collection;)Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=4, locals=6, args_size=2
        start local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
        start local 1 // java.util.Collection c
         0: .line 4659
            iconst_0
            istore 2 /* added */
        start local 2 // boolean added
         1: .line 4661
            aload 0 /* this */
            getfield java.util.concurrent.ConcurrentHashMap$KeySetView.value:Ljava/lang/Object;
            dup
            astore 3 /* v */
        start local 3 // java.lang.Object v
         2: ifnonnull 4
         3: .line 4662
            new java.lang.UnsupportedOperationException
            dup
            invokespecial java.lang.UnsupportedOperationException.<init>:()V
            athrow
         4: .line 4663
      StackMap locals: int java.lang.Object
      StackMap stack:
            aload 1 /* c */
            invokeinterface java.util.Collection.iterator:()Ljava/util/Iterator;
            astore 5
            goto 8
      StackMap locals: java.util.concurrent.ConcurrentHashMap$KeySetView java.util.Collection int java.lang.Object top java.util.Iterator
      StackMap stack:
         5: aload 5
            invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
            checkcast java.lang.Object
            astore 4 /* e */
        start local 4 // java.lang.Object e
         6: .line 4664
            aload 0 /* this */
            getfield java.util.concurrent.ConcurrentHashMap$KeySetView.map:Ljava/util/concurrent/ConcurrentHashMap;
            aload 4 /* e */
            aload 3 /* v */
            iconst_1
            invokevirtual java.util.concurrent.ConcurrentHashMap.putVal:(Ljava/lang/Object;Ljava/lang/Object;Z)Ljava/lang/Object;
            ifnonnull 8
         7: .line 4665
            iconst_1
            istore 2 /* added */
        end local 4 // java.lang.Object e
         8: .line 4663
      StackMap locals:
      StackMap stack:
            aload 5
            invokeinterface java.util.Iterator.hasNext:()Z
            ifne 5
         9: .line 4667
            iload 2 /* added */
            ireturn
        end local 3 // java.lang.Object v
        end local 2 // boolean added
        end local 1 // java.util.Collection c
        end local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0   10     0   this  Ljava/util/concurrent/ConcurrentHashMap$KeySetView<TK;TV;>;
            0   10     1      c  Ljava/util/Collection<+TK;>;
            1   10     2  added  Z
            2   10     3      v  TV;
            6    8     4      e  TK;
    Signature: (Ljava/util/Collection<+TK;>;)Z
    MethodParameters:
      Name  Flags
      c     

  public int hashCode();
    descriptor: ()I
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=4, args_size=1
        start local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
         0: .line 4671
            iconst_0
            istore 1 /* h */
        start local 1 // int h
         1: .line 4672
            aload 0 /* this */
            invokevirtual java.util.concurrent.ConcurrentHashMap$KeySetView.iterator:()Ljava/util/Iterator;
            astore 3
            goto 4
      StackMap locals: java.util.concurrent.ConcurrentHashMap$KeySetView int top java.util.Iterator
      StackMap stack:
         2: aload 3
            invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
            checkcast java.lang.Object
            astore 2 /* e */
        start local 2 // java.lang.Object e
         3: .line 4673
            iload 1 /* h */
            aload 2 /* e */
            invokevirtual java.lang.Object.hashCode:()I
            iadd
            istore 1 /* h */
        end local 2 // java.lang.Object e
         4: .line 4672
      StackMap locals:
      StackMap stack:
            aload 3
            invokeinterface java.util.Iterator.hasNext:()Z
            ifne 2
         5: .line 4674
            iload 1 /* h */
            ireturn
        end local 1 // int h
        end local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    6     0  this  Ljava/util/concurrent/ConcurrentHashMap$KeySetView<TK;TV;>;
            1    6     1     h  I
            3    4     2     e  TK;

  public boolean equals(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=3, args_size=2
        start local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
        start local 1 // java.lang.Object o
         0: .line 4679
            aload 1 /* o */
            instanceof java.util.Set
            ifeq 5
         1: .line 4680
            aload 1 /* o */
            checkcast java.util.Set
            dup
            astore 2 /* c */
        start local 2 // java.util.Set c
         2: aload 0 /* this */
            if_acmpeq 4
         3: .line 4681
            aload 0 /* this */
            aload 2 /* c */
            invokevirtual java.util.concurrent.ConcurrentHashMap$KeySetView.containsAll:(Ljava/util/Collection;)Z
            ifeq 5
            aload 2 /* c */
            aload 0 /* this */
            invokeinterface java.util.Set.containsAll:(Ljava/util/Collection;)Z
            ifeq 5
        end local 2 // java.util.Set c
         4: .line 4679
      StackMap locals:
      StackMap stack:
            iconst_1
            ireturn
      StackMap locals:
      StackMap stack:
         5: iconst_0
            ireturn
        end local 1 // java.lang.Object o
        end local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    6     0  this  Ljava/util/concurrent/ConcurrentHashMap$KeySetView<TK;TV;>;
            0    6     1     o  Ljava/lang/Object;
            2    4     2     c  Ljava/util/Set<*>;
    MethodParameters:
      Name  Flags
      o     

  public java.util.Spliterator<K> spliterator();
    descriptor: ()Ljava/util/Spliterator;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=10, locals=6, args_size=1
        start local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
         0: .line 4686
            aload 0 /* this */
            getfield java.util.concurrent.ConcurrentHashMap$KeySetView.map:Ljava/util/concurrent/ConcurrentHashMap;
            astore 2 /* m */
        start local 2 // java.util.concurrent.ConcurrentHashMap m
         1: .line 4687
            aload 2 /* m */
            invokevirtual java.util.concurrent.ConcurrentHashMap.sumCount:()J
            lstore 3 /* n */
        start local 3 // long n
         2: .line 4688
            aload 2 /* m */
            getfield java.util.concurrent.ConcurrentHashMap.table:[Ljava/util/concurrent/ConcurrentHashMap$Node;
            dup
            astore 1 /* t */
        start local 1 // java.util.concurrent.ConcurrentHashMap$Node[] t
         3: ifnonnull 4
            iconst_0
            goto 5
      StackMap locals: java.util.concurrent.ConcurrentHashMap$Node[] java.util.concurrent.ConcurrentHashMap long
      StackMap stack:
         4: aload 1 /* t */
            arraylength
      StackMap locals:
      StackMap stack: int
         5: istore 5 /* f */
        start local 5 // int f
         6: .line 4689
            new java.util.concurrent.ConcurrentHashMap$KeySpliterator
            dup
            aload 1 /* t */
            iload 5 /* f */
            iconst_0
            iload 5 /* f */
            lload 3 /* n */
            lconst_0
            lcmp
            ifge 7
            lconst_0
            goto 8
      StackMap locals: java.util.concurrent.ConcurrentHashMap$KeySetView java.util.concurrent.ConcurrentHashMap$Node[] java.util.concurrent.ConcurrentHashMap long int
      StackMap stack: new 6 new 6 java.util.concurrent.ConcurrentHashMap$Node[] int int int
         7: lload 3 /* n */
      StackMap locals: java.util.concurrent.ConcurrentHashMap$KeySetView java.util.concurrent.ConcurrentHashMap$Node[] java.util.concurrent.ConcurrentHashMap long int
      StackMap stack: new 6 new 6 java.util.concurrent.ConcurrentHashMap$Node[] int int int long
         8: invokespecial java.util.concurrent.ConcurrentHashMap$KeySpliterator.<init>:([Ljava/util/concurrent/ConcurrentHashMap$Node;IIIJ)V
            areturn
        end local 5 // int f
        end local 3 // long n
        end local 2 // java.util.concurrent.ConcurrentHashMap m
        end local 1 // java.util.concurrent.ConcurrentHashMap$Node[] t
        end local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    9     0  this  Ljava/util/concurrent/ConcurrentHashMap$KeySetView<TK;TV;>;
            3    9     1     t  [Ljava/util/concurrent/ConcurrentHashMap$Node;
            1    9     2     m  Ljava/util/concurrent/ConcurrentHashMap<TK;TV;>;
            2    9     3     n  J
            6    9     5     f  I
    Signature: ()Ljava/util/Spliterator<TK;>;

  public void forEach(java.util.function.Consumer<? super K>);
    descriptor: (Ljava/util/function/Consumer;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=6, locals=5, args_size=2
        start local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
        start local 1 // java.util.function.Consumer action
         0: .line 4693
            aload 1 /* action */
            ifnonnull 1
            new java.lang.NullPointerException
            dup
            invokespecial java.lang.NullPointerException.<init>:()V
            athrow
         1: .line 4695
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield java.util.concurrent.ConcurrentHashMap$KeySetView.map:Ljava/util/concurrent/ConcurrentHashMap;
            getfield java.util.concurrent.ConcurrentHashMap.table:[Ljava/util/concurrent/ConcurrentHashMap$Node;
            dup
            astore 2 /* t */
        start local 2 // java.util.concurrent.ConcurrentHashMap$Node[] t
         2: ifnull 8
         3: .line 4696
            new java.util.concurrent.ConcurrentHashMap$Traverser
            dup
            aload 2 /* t */
            aload 2 /* t */
            arraylength
            iconst_0
            aload 2 /* t */
            arraylength
            invokespecial java.util.concurrent.ConcurrentHashMap$Traverser.<init>:([Ljava/util/concurrent/ConcurrentHashMap$Node;III)V
            astore 3 /* it */
        start local 3 // java.util.concurrent.ConcurrentHashMap$Traverser it
         4: .line 4697
            goto 6
        start local 4 // java.util.concurrent.ConcurrentHashMap$Node p
         5: .line 4698
      StackMap locals: java.util.concurrent.ConcurrentHashMap$Node[] java.util.concurrent.ConcurrentHashMap$Traverser java.util.concurrent.ConcurrentHashMap$Node
      StackMap stack:
            aload 1 /* action */
            aload 4 /* p */
            getfield java.util.concurrent.ConcurrentHashMap$Node.key:Ljava/lang/Object;
            invokeinterface java.util.function.Consumer.accept:(Ljava/lang/Object;)V
        end local 4 // java.util.concurrent.ConcurrentHashMap$Node p
         6: .line 4697
      StackMap locals:
      StackMap stack:
            aload 3 /* it */
            invokevirtual java.util.concurrent.ConcurrentHashMap$Traverser.advance:()Ljava/util/concurrent/ConcurrentHashMap$Node;
            dup
            astore 4 /* p */
        start local 4 // java.util.concurrent.ConcurrentHashMap$Node p
         7: ifnonnull 5
        end local 4 // java.util.concurrent.ConcurrentHashMap$Node p
        end local 3 // java.util.concurrent.ConcurrentHashMap$Traverser it
         8: .line 4700
      StackMap locals:
      StackMap stack:
            return
        end local 2 // java.util.concurrent.ConcurrentHashMap$Node[] t
        end local 1 // java.util.function.Consumer action
        end local 0 // java.util.concurrent.ConcurrentHashMap$KeySetView this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    9     0    this  Ljava/util/concurrent/ConcurrentHashMap$KeySetView<TK;TV;>;
            0    9     1  action  Ljava/util/function/Consumer<-TK;>;
            2    9     2       t  [Ljava/util/concurrent/ConcurrentHashMap$Node;
            4    8     3      it  Ljava/util/concurrent/ConcurrentHashMap$Traverser<TK;TV;>;
            5    6     4       p  Ljava/util/concurrent/ConcurrentHashMap$Node<TK;TV;>;
            7    8     4       p  Ljava/util/concurrent/ConcurrentHashMap$Node<TK;TV;>;
    Signature: (Ljava/util/function/Consumer<-TK;>;)V
    MethodParameters:
        Name  Flags
      action  

  public boolean removeAll(java.util.Collection);
    descriptor: (Ljava/util/Collection;)Z
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=2, locals=2, args_size=2
         0: .line 1
            aload 0
            aload 1
            invokespecial java.util.concurrent.ConcurrentHashMap$CollectionView.removeAll:(Ljava/util/Collection;)Z
            ireturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  public java.util.concurrent.ConcurrentHashMap getMap();
    descriptor: ()Ljava/util/concurrent/ConcurrentHashMap;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=1, locals=1, args_size=1
         0: .line 1
            aload 0
            invokespecial java.util.concurrent.ConcurrentHashMap$CollectionView.getMap:()Ljava/util/concurrent/ConcurrentHashMap;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
}
Signature: <K:Ljava/lang/Object;V:Ljava/lang/Object;>Ljava/util/concurrent/ConcurrentHashMap$CollectionView<TK;TV;TK;>;Ljava/util/Set<TK;>;Ljava/io/Serializable;
SourceFile: "ConcurrentHashMap.java"
NestHost: java.util.concurrent.ConcurrentHashMap
InnerClasses:
  abstract CollectionView = java.util.concurrent.ConcurrentHashMap$CollectionView of java.util.concurrent.ConcurrentHashMap
  final KeyIterator = java.util.concurrent.ConcurrentHashMap$KeyIterator of java.util.concurrent.ConcurrentHashMap
  public KeySetView = java.util.concurrent.ConcurrentHashMap$KeySetView of java.util.concurrent.ConcurrentHashMap
  final KeySpliterator = java.util.concurrent.ConcurrentHashMap$KeySpliterator of java.util.concurrent.ConcurrentHashMap
  Node = java.util.concurrent.ConcurrentHashMap$Node of java.util.concurrent.ConcurrentHashMap
  Traverser = java.util.concurrent.ConcurrentHashMap$Traverser of java.util.concurrent.ConcurrentHashMap