https://www.graalvm.org/ 
abstract class org.graalvm.compiler.truffle.test.LibraryCompilationTest$CompilationLibrary extends com.oracle.truffle.api.library.Library
  minor version: 0
  major version: 59
  flags: flags: (0x0420) ACC_SUPER, ACC_ABSTRACT
  this_class: org.graalvm.compiler.truffle.test.LibraryCompilationTest$CompilationLibrary
  super_class: com.oracle.truffle.api.library.Library
{
  void <init>();
    descriptor: ()V
    flags: (0x0000) 
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.graalvm.compiler.truffle.test.LibraryCompilationTest$CompilationLibrary this
         0: .line 45
            aload 0 /* this */
            invokespecial com.oracle.truffle.api.library.Library.<init>:()V
            return
        end local 0 // org.graalvm.compiler.truffle.test.LibraryCompilationTest$CompilationLibrary this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/graalvm/compiler/truffle/test/LibraryCompilationTest$CompilationLibrary;

  public abstract java.lang.Object foldAsConstant(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Ljava/lang/Object;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
          Name  Flags
      receiver  
}
SourceFile: "LibraryCompilationTest.java"
NestHost: org.graalvm.compiler.truffle.test.LibraryCompilationTest
InnerClasses:
  abstract CompilationLibrary = org.graalvm.compiler.truffle.test.LibraryCompilationTest$CompilationLibrary of org.graalvm.compiler.truffle.test.LibraryCompilationTest
    RuntimeVisibleAnnotations: 
      com.oracle.truffle.api.library.GenerateLibrary()