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.Double2LongMap$FastEntrySet extends it.unimi.dsi.fastutil.objects.ObjectSet<it.unimi.dsi.fastutil.doubles.Double2LongMap$Entry>
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: it.unimi.dsi.fastutil.doubles.Double2LongMap$FastEntrySet
  super_class: java.lang.Object
{
  public abstract it.unimi.dsi.fastutil.objects.ObjectIterator<it.unimi.dsi.fastutil.doubles.Double2LongMap$Entry> fastIterator();
    descriptor: ()Lit/unimi/dsi/fastutil/objects/ObjectIterator;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Signature: ()Lit/unimi/dsi/fastutil/objects/ObjectIterator<Lit/unimi/dsi/fastutil/doubles/Double2LongMap$Entry;>;

  public void fastForEach(java.util.function.Consumer<? super it.unimi.dsi.fastutil.doubles.Double2LongMap$Entry>);
    descriptor: (Ljava/util/function/Consumer;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // it.unimi.dsi.fastutil.doubles.Double2LongMap$FastEntrySet this
        start local 1 // java.util.function.Consumer consumer
         0: .line 80
            aload 0 /* this */
            aload 1 /* consumer */
            invokeinterface it.unimi.dsi.fastutil.doubles.Double2LongMap$FastEntrySet.forEach:(Ljava/util/function/Consumer;)V
         1: .line 81
            return
        end local 1 // java.util.function.Consumer consumer
        end local 0 // it.unimi.dsi.fastutil.doubles.Double2LongMap$FastEntrySet this
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            0    2     0      this  Lit/unimi/dsi/fastutil/doubles/Double2LongMap$FastEntrySet;
            0    2     1  consumer  Ljava/util/function/Consumer<-Lit/unimi/dsi/fastutil/doubles/Double2LongMap$Entry;>;
    Signature: (Ljava/util/function/Consumer<-Lit/unimi/dsi/fastutil/doubles/Double2LongMap$Entry;>;)V
    MethodParameters:
          Name  Flags
      consumer  final
}
Signature: Ljava/lang/Object;Lit/unimi/dsi/fastutil/objects/ObjectSet<Lit/unimi/dsi/fastutil/doubles/Double2LongMap$Entry;>;
SourceFile: "Double2LongMap.java"
NestHost: it.unimi.dsi.fastutil.doubles.Double2LongMap
InnerClasses:
  public abstract Entry = it.unimi.dsi.fastutil.doubles.Double2LongMap$Entry of it.unimi.dsi.fastutil.doubles.Double2LongMap
  public abstract FastEntrySet = it.unimi.dsi.fastutil.doubles.Double2LongMap$FastEntrySet of it.unimi.dsi.fastutil.doubles.Double2LongMap