http://fastutil.di.unimi.it/: fastutil extends the Java Collections Framework by providing type-specific maps, sets, lists and priority queues with a small memory footprint and fast access and insertion; provides also big (64-bit) arrays, sets and lists, and fast, practical I/O classes for binary and text files.
  • Sebastiano Vigna 
class it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeySet extends it.unimi.dsi.fastutil.longs.AbstractLong2ObjectSortedMap<V>.KeySet
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeySet
  super_class: it.unimi.dsi.fastutil.longs.AbstractLong2ObjectSortedMap$KeySet
{
  final it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap this$0;
    descriptor: Lit/unimi/dsi/fastutil/longs/Long2ObjectRBTreeMap;
    flags: (0x1010) ACC_FINAL, ACC_SYNTHETIC

  private void <init>(it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap);
    descriptor: (Lit/unimi/dsi/fastutil/longs/Long2ObjectRBTreeMap;)V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeySet this
         0: .line 1176
            aload 0 /* this */
            aload 1
            putfield it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeySet.this$0:Lit/unimi/dsi/fastutil/longs/Long2ObjectRBTreeMap;
            aload 0 /* this */
            aload 1
            invokespecial it.unimi.dsi.fastutil.longs.AbstractLong2ObjectSortedMap$KeySet.<init>:(Lit/unimi/dsi/fastutil/longs/AbstractLong2ObjectSortedMap;)V
            return
        end local 0 // it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeySet this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lit/unimi/dsi/fastutil/longs/Long2ObjectRBTreeMap$KeySet;
    MethodParameters:
        Name  Flags
      this$0  final

  public it.unimi.dsi.fastutil.longs.LongBidirectionalIterator iterator();
    descriptor: ()Lit/unimi/dsi/fastutil/longs/LongBidirectionalIterator;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeySet this
         0: .line 1179
            new it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeyIterator
            dup
            aload 0 /* this */
            getfield it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeySet.this$0:Lit/unimi/dsi/fastutil/longs/Long2ObjectRBTreeMap;
            invokespecial it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeyIterator.<init>:(Lit/unimi/dsi/fastutil/longs/Long2ObjectRBTreeMap;)V
            areturn
        end local 0 // it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeySet this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lit/unimi/dsi/fastutil/longs/Long2ObjectRBTreeMap$KeySet;

  public it.unimi.dsi.fastutil.longs.LongBidirectionalIterator iterator(long);
    descriptor: (J)Lit/unimi/dsi/fastutil/longs/LongBidirectionalIterator;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=5, locals=3, args_size=2
        start local 0 // it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeySet this
        start local 1 // long from
         0: .line 1183
            new it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeyIterator
            dup
            aload 0 /* this */
            getfield it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeySet.this$0:Lit/unimi/dsi/fastutil/longs/Long2ObjectRBTreeMap;
            lload 1 /* from */
            invokespecial it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeyIterator.<init>:(Lit/unimi/dsi/fastutil/longs/Long2ObjectRBTreeMap;J)V
            areturn
        end local 1 // long from
        end local 0 // it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeySet this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lit/unimi/dsi/fastutil/longs/Long2ObjectRBTreeMap$KeySet;
            0    1     1  from  J
    MethodParameters:
      Name  Flags
      from  final

  public java.util.Iterator iterator();
    descriptor: ()Ljava/util/Iterator;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=1, locals=1, args_size=1
         0: .line 1
            aload 0
            invokevirtual it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeySet.iterator:()Lit/unimi/dsi/fastutil/longs/LongBidirectionalIterator;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  public it.unimi.dsi.fastutil.longs.LongIterator iterator();
    descriptor: ()Lit/unimi/dsi/fastutil/longs/LongIterator;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=1, locals=1, args_size=1
         0: .line 1
            aload 0
            invokevirtual it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeySet.iterator:()Lit/unimi/dsi/fastutil/longs/LongBidirectionalIterator;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
}
Signature: Lit/unimi/dsi/fastutil/longs/AbstractLong2ObjectSortedMap<TV;>.KeySet;
SourceFile: "Long2ObjectRBTreeMap.java"
NestHost: it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap
InnerClasses:
  protected KeySet = it.unimi.dsi.fastutil.longs.AbstractLong2ObjectSortedMap$KeySet of it.unimi.dsi.fastutil.longs.AbstractLong2ObjectSortedMap
  private final KeyIterator = it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeyIterator of it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap
  private KeySet = it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap$KeySet of it.unimi.dsi.fastutil.longs.Long2ObjectRBTreeMap