https://github.com/eclipse/eclipse-collections/eclipse-collections: 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 
final class org.eclipse.collections.impl.block.factory.Functions$DefaultFunction<T, V> implements org.eclipse.collections.api.block.function.Function<T, V>
  minor version: 0
  major version: 59
  flags: flags: (0x0030) ACC_FINAL, ACC_SUPER
  this_class: org.eclipse.collections.impl.block.factory.Functions$DefaultFunction
  super_class: java.lang.Object
{
  private static final long serialVersionUID;
    descriptor: J
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    ConstantValue: 1

  private final org.eclipse.collections.api.block.function.Function<? super T, ? extends V> function;
    descriptor: Lorg/eclipse/collections/api/block/function/Function;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Lorg/eclipse/collections/api/block/function/Function<-TT;+TV;>;

  private final V defaultValue;
    descriptor: Ljava/lang/Object;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: TV;

  private void <init>(org.eclipse.collections.api.block.function.Function<? super T, ? extends V>, );
    descriptor: (Lorg/eclipse/collections/api/block/function/Function;Ljava/lang/Object;)V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=2, locals=3, args_size=3
        start local 0 // org.eclipse.collections.impl.block.factory.Functions$DefaultFunction this
        start local 1 // org.eclipse.collections.api.block.function.Function newFunction
        start local 2 // java.lang.Object newDefaultValue
         0: .line 741
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 743
            aload 0 /* this */
            aload 1 /* newFunction */
            putfield org.eclipse.collections.impl.block.factory.Functions$DefaultFunction.function:Lorg/eclipse/collections/api/block/function/Function;
         2: .line 744
            aload 0 /* this */
            aload 2 /* newDefaultValue */
            putfield org.eclipse.collections.impl.block.factory.Functions$DefaultFunction.defaultValue:Ljava/lang/Object;
         3: .line 745
            return
        end local 2 // java.lang.Object newDefaultValue
        end local 1 // org.eclipse.collections.api.block.function.Function newFunction
        end local 0 // org.eclipse.collections.impl.block.factory.Functions$DefaultFunction this
      LocalVariableTable:
        Start  End  Slot             Name  Signature
            0    4     0             this  Lorg/eclipse/collections/impl/block/factory/Functions$DefaultFunction<TT;TV;>;
            0    4     1      newFunction  Lorg/eclipse/collections/api/block/function/Function<-TT;+TV;>;
            0    4     2  newDefaultValue  TV;
    Signature: (Lorg/eclipse/collections/api/block/function/Function<-TT;+TV;>;TV;)V
    MethodParameters:
                 Name  Flags
      newFunction      
      newDefaultValue  

  public V valueOf();
    descriptor: (Ljava/lang/Object;)Ljava/lang/Object;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=3, args_size=2
        start local 0 // org.eclipse.collections.impl.block.factory.Functions$DefaultFunction this
        start local 1 // java.lang.Object anObject
         0: .line 750
            aload 0 /* this */
            getfield org.eclipse.collections.impl.block.factory.Functions$DefaultFunction.function:Lorg/eclipse/collections/api/block/function/Function;
            aload 1 /* anObject */
            invokeinterface org.eclipse.collections.api.block.function.Function.valueOf:(Ljava/lang/Object;)Ljava/lang/Object;
            astore 2 /* returnValue */
        start local 2 // java.lang.Object returnValue
         1: .line 751
            aload 2 /* returnValue */
            ifnonnull 3
         2: .line 753
            aload 0 /* this */
            getfield org.eclipse.collections.impl.block.factory.Functions$DefaultFunction.defaultValue:Ljava/lang/Object;
            areturn
         3: .line 755
      StackMap locals: java.lang.Object
      StackMap stack:
            aload 2 /* returnValue */
            areturn
        end local 2 // java.lang.Object returnValue
        end local 1 // java.lang.Object anObject
        end local 0 // org.eclipse.collections.impl.block.factory.Functions$DefaultFunction this
      LocalVariableTable:
        Start  End  Slot         Name  Signature
            0    4     0         this  Lorg/eclipse/collections/impl/block/factory/Functions$DefaultFunction<TT;TV;>;
            0    4     1     anObject  TT;
            1    4     2  returnValue  TV;
    Signature: (TT;)TV;
    MethodParameters:
          Name  Flags
      anObject  
}
Signature: <T:Ljava/lang/Object;V:Ljava/lang/Object;>Ljava/lang/Object;Lorg/eclipse/collections/api/block/function/Function<TT;TV;>;
SourceFile: "Functions.java"
NestHost: org.eclipse.collections.impl.block.factory.Functions
InnerClasses:
  private final DefaultFunction = org.eclipse.collections.impl.block.factory.Functions$DefaultFunction of org.eclipse.collections.impl.block.factory.Functions