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 
final class org.eclipse.collections.impl.block.factory.Functions$SynchronizedFunction<T, V> implements org.eclipse.collections.api.block.function.Function<T, V>
  minor version: 0
  major version: 59
  flags: flags: (0x0030) ACC_FINAL, ACC_SUPER
  this_class: org.eclipse.collections.impl.block.factory.Functions$SynchronizedFunction
  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<T, 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 void <init>(org.eclipse.collections.api.block.function.Function<T, V>);
    descriptor: (Lorg/eclipse/collections/api/block/function/Function;)V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // org.eclipse.collections.impl.block.factory.Functions$SynchronizedFunction this
        start local 1 // org.eclipse.collections.api.block.function.Function function
         0: .line 606
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 608
            aload 0 /* this */
            aload 1 /* function */
            putfield org.eclipse.collections.impl.block.factory.Functions$SynchronizedFunction.function:Lorg/eclipse/collections/api/block/function/Function;
         2: .line 609
            return
        end local 1 // org.eclipse.collections.api.block.function.Function function
        end local 0 // org.eclipse.collections.impl.block.factory.Functions$SynchronizedFunction this
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            0    3     0      this  Lorg/eclipse/collections/impl/block/factory/Functions$SynchronizedFunction<TT;TV;>;
            0    3     1  function  Lorg/eclipse/collections/api/block/function/Function<TT;TV;>;
    Signature: (Lorg/eclipse/collections/api/block/function/Function<TT;TV;>;)V
    MethodParameters:
          Name  Flags
      function  

  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$SynchronizedFunction this
        start local 1 // java.lang.Object each
         0: .line 614
            aload 1 /* each */
            dup
            astore 2
            monitorenter
         1: .line 616
            aload 0 /* this */
            getfield org.eclipse.collections.impl.block.factory.Functions$SynchronizedFunction.function:Lorg/eclipse/collections/api/block/function/Function;
            aload 1 /* each */
            invokeinterface org.eclipse.collections.api.block.function.Function.valueOf:(Ljava/lang/Object;)Ljava/lang/Object;
            aload 2
            monitorexit
         2: areturn
         3: .line 614
      StackMap locals: org.eclipse.collections.impl.block.factory.Functions$SynchronizedFunction java.lang.Object java.lang.Object
      StackMap stack: java.lang.Throwable
            aload 2
            monitorexit
         4: athrow
        end local 1 // java.lang.Object each
        end local 0 // org.eclipse.collections.impl.block.factory.Functions$SynchronizedFunction this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    5     0  this  Lorg/eclipse/collections/impl/block/factory/Functions$SynchronizedFunction<TT;TV;>;
            0    5     1  each  TT;
      Exception table:
        from    to  target  type
           1     2       3  any
           3     4       3  any
    Signature: (TT;)TV;
    MethodParameters:
      Name  Flags
      each  
}
Signature: <T:Ljava/lang/Object;V:Ljava/lang/Object;>Ljava/lang/Object;Lorg/eclipse/collections/api/block/function/Function<TT;TV;>;
SourceFile: "Functions.java"
NestHost: org.eclipse.collections.impl.block.factory.Functions
InnerClasses:
  private final SynchronizedFunction = org.eclipse.collections.impl.block.factory.Functions$SynchronizedFunction of org.eclipse.collections.impl.block.factory.Functions