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.BidirectionalIterator<K> extends java.util.Iterator<K>
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: it.unimi.dsi.fastutil.BidirectionalIterator
  super_class: java.lang.Object
{
  public abstract K previous();
    descriptor: ()Ljava/lang/Object;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Signature: ()TK;

  public abstract boolean hasPrevious();
    descriptor: ()Z
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
}
Signature: <K:Ljava/lang/Object;>Ljava/lang/Object;Ljava/util/Iterator<TK;>;
SourceFile: "BidirectionalIterator.java"