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
  • Sirisha Pratha 
public interface org.eclipse.collections.api.block.function.primitive.LongToLongFunction extends java.util.function.LongUnaryOperator, java.io.Serializable
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: org.eclipse.collections.api.block.function.primitive.LongToLongFunction
  super_class: java.lang.Object
{
  public abstract long valueOf(long);
    descriptor: (J)J
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
               Name  Flags
      longParameter  

  public long applyAsLong(long);
    descriptor: (J)J
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=2
        start local 0 // org.eclipse.collections.api.block.function.primitive.LongToLongFunction this
        start local 1 // long each
         0: .line 29
            aload 0 /* this */
            lload 1 /* each */
            invokeinterface org.eclipse.collections.api.block.function.primitive.LongToLongFunction.valueOf:(J)J
            lreturn
        end local 1 // long each
        end local 0 // org.eclipse.collections.api.block.function.primitive.LongToLongFunction this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/eclipse/collections/api/block/function/primitive/LongToLongFunction;
            0    1     1  each  J
    MethodParameters:
      Name  Flags
      each  
}
SourceFile: "LongToLongFunction.java"
    RuntimeVisibleAnnotations: 
      java.lang.FunctionalInterface()