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 
public interface it.unimi.dsi.fastutil.doubles.Double2BooleanSortedMap$FastSortedEntrySet extends it.unimi.dsi.fastutil.objects.ObjectSortedSet<it.unimi.dsi.fastutil.doubles.Double2BooleanMap$Entry>, it.unimi.dsi.fastutil.doubles.Double2BooleanMap$FastEntrySet
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: it.unimi.dsi.fastutil.doubles.Double2BooleanSortedMap$FastSortedEntrySet
  super_class: java.lang.Object
{
  public abstract it.unimi.dsi.fastutil.objects.ObjectBidirectionalIterator<it.unimi.dsi.fastutil.doubles.Double2BooleanMap$Entry> fastIterator();
    descriptor: ()Lit/unimi/dsi/fastutil/objects/ObjectBidirectionalIterator;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Signature: ()Lit/unimi/dsi/fastutil/objects/ObjectBidirectionalIterator<Lit/unimi/dsi/fastutil/doubles/Double2BooleanMap$Entry;>;

  public abstract it.unimi.dsi.fastutil.objects.ObjectBidirectionalIterator<it.unimi.dsi.fastutil.doubles.Double2BooleanMap$Entry> fastIterator(it.unimi.dsi.fastutil.doubles.Double2BooleanMap$Entry);
    descriptor: (Lit/unimi/dsi/fastutil/doubles/Double2BooleanMap$Entry;)Lit/unimi/dsi/fastutil/objects/ObjectBidirectionalIterator;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Signature: (Lit/unimi/dsi/fastutil/doubles/Double2BooleanMap$Entry;)Lit/unimi/dsi/fastutil/objects/ObjectBidirectionalIterator<Lit/unimi/dsi/fastutil/doubles/Double2BooleanMap$Entry;>;
    MethodParameters:
      Name  Flags
      from  

  public it.unimi.dsi.fastutil.objects.ObjectIterator fastIterator();
    descriptor: ()Lit/unimi/dsi/fastutil/objects/ObjectIterator;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=1, locals=1, args_size=1
         0: .line 1
            aload 0
            invokeinterface it.unimi.dsi.fastutil.doubles.Double2BooleanSortedMap$FastSortedEntrySet.fastIterator:()Lit/unimi/dsi/fastutil/objects/ObjectBidirectionalIterator;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
}
Signature: Ljava/lang/Object;Lit/unimi/dsi/fastutil/objects/ObjectSortedSet<Lit/unimi/dsi/fastutil/doubles/Double2BooleanMap$Entry;>;Lit/unimi/dsi/fastutil/doubles/Double2BooleanMap$FastEntrySet;
SourceFile: "Double2BooleanSortedMap.java"
NestHost: it.unimi.dsi.fastutil.doubles.Double2BooleanSortedMap
InnerClasses:
  public abstract Entry = it.unimi.dsi.fastutil.doubles.Double2BooleanMap$Entry of it.unimi.dsi.fastutil.doubles.Double2BooleanMap
  public abstract FastEntrySet = it.unimi.dsi.fastutil.doubles.Double2BooleanMap$FastEntrySet of it.unimi.dsi.fastutil.doubles.Double2BooleanMap
  public abstract FastSortedEntrySet = it.unimi.dsi.fastutil.doubles.Double2BooleanSortedMap$FastSortedEntrySet of it.unimi.dsi.fastutil.doubles.Double2BooleanSortedMap