https://github.com/eclipse/eclipse-collections/eclipse-collections-api: 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 
public interface org.eclipse.collections.api.tuple.Twin<T> extends org.eclipse.collections.api.tuple.Pair<T, T>
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: org.eclipse.collections.api.tuple.Twin
  super_class: java.lang.Object
{
  public abstract org.eclipse.collections.api.tuple.Twin<T> swap();
    descriptor: ()Lorg/eclipse/collections/api/tuple/Twin;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Signature: ()Lorg/eclipse/collections/api/tuple/Twin<TT;>;

  public org.eclipse.collections.api.tuple.Pair swap();
    descriptor: ()Lorg/eclipse/collections/api/tuple/Pair;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=1, locals=1, args_size=1
         0: .line 1
            aload 0
            invokeinterface org.eclipse.collections.api.tuple.Twin.swap:()Lorg/eclipse/collections/api/tuple/Twin;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
}
Signature: <T:Ljava/lang/Object;>Ljava/lang/Object;Lorg/eclipse/collections/api/tuple/Pair<TT;TT;>;
SourceFile: "Twin.java"