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 
final class org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$KeyIterator extends org.eclipse.collections.impl.map.mutable.ConcurrentHashMap<K, V>.HashIterator<K>
  minor version: 0
  major version: 59
  flags: flags: (0x0030) ACC_FINAL, ACC_SUPER
  this_class: org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$KeyIterator
  super_class: org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$HashIterator
{
  final org.eclipse.collections.impl.map.mutable.ConcurrentHashMap this$0;
    descriptor: Lorg/eclipse/collections/impl/map/mutable/ConcurrentHashMap;
    flags: (0x1010) ACC_FINAL, ACC_SYNTHETIC

  private void <init>(org.eclipse.collections.impl.map.mutable.ConcurrentHashMap);
    descriptor: (Lorg/eclipse/collections/impl/map/mutable/ConcurrentHashMap;)V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$KeyIterator this
         0: .line 1594
            aload 0 /* this */
            aload 1
            putfield org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$KeyIterator.this$0:Lorg/eclipse/collections/impl/map/mutable/ConcurrentHashMap;
            aload 0 /* this */
            aload 1
            invokespecial org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$HashIterator.<init>:(Lorg/eclipse/collections/impl/map/mutable/ConcurrentHashMap;)V
            return
        end local 0 // org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$KeyIterator this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/eclipse/collections/impl/map/mutable/ConcurrentHashMap$KeyIterator;
    MethodParameters:
        Name  Flags
      this$0  final

  public K next();
    descriptor: ()Ljava/lang/Object;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$KeyIterator this
         0: .line 1599
            aload 0 /* this */
            invokevirtual org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$KeyIterator.nextEntry:()Lorg/eclipse/collections/impl/map/mutable/ConcurrentHashMap$Entry;
            invokevirtual org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$Entry.getKey:()Ljava/lang/Object;
            areturn
        end local 0 // org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$KeyIterator this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/eclipse/collections/impl/map/mutable/ConcurrentHashMap$KeyIterator;
    Signature: ()TK;

  public void remove();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$KeyIterator this
         0: .line 1605
            aload 0 /* this */
            invokevirtual org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$KeyIterator.removeByKey:()V
         1: .line 1606
            return
        end local 0 // org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$KeyIterator this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lorg/eclipse/collections/impl/map/mutable/ConcurrentHashMap$KeyIterator;
}
Signature: Lorg/eclipse/collections/impl/map/mutable/ConcurrentHashMap<TK;TV;>.HashIterator<TK;>;
SourceFile: "ConcurrentHashMap.java"
NestHost: org.eclipse.collections.impl.map.mutable.ConcurrentHashMap
InnerClasses:
  private final Entry = org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$Entry of org.eclipse.collections.impl.map.mutable.ConcurrentHashMap
  private abstract HashIterator = org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$HashIterator of org.eclipse.collections.impl.map.mutable.ConcurrentHashMap
  private final KeyIterator = org.eclipse.collections.impl.map.mutable.ConcurrentHashMap$KeyIterator of org.eclipse.collections.impl.map.mutable.ConcurrentHashMap