https://www.graalvm.org/ 
class com.oracle.truffle.trufflenode.GraalJSAccess$NodeScriptOrModule extends com.oracle.truffle.js.runtime.objects.ScriptOrModule
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.oracle.truffle.trufflenode.GraalJSAccess$NodeScriptOrModule
  super_class: com.oracle.truffle.js.runtime.objects.ScriptOrModule
{
  static final com.oracle.truffle.api.object.HiddenKey SCRIPT_OR_MODULE;
    descriptor: Lcom/oracle/truffle/api/object/HiddenKey;
    flags: (0x0018) ACC_STATIC, ACC_FINAL

  private java.util.Map<java.lang.Long, com.oracle.truffle.trufflenode.GraalJSAccess$WeakCallback> weakCallbackMap;
    descriptor: Ljava/util/Map;
    flags: (0x0002) ACC_PRIVATE
    Signature: Ljava/util/Map<Ljava/lang/Long;Lcom/oracle/truffle/trufflenode/GraalJSAccess$WeakCallback;>;

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=3, locals=0, args_size=0
         0: .line 3600
            new com.oracle.truffle.api.object.HiddenKey
            dup
            ldc "scriptOrModule"
            invokespecial com.oracle.truffle.api.object.HiddenKey.<init>:(Ljava/lang/String;)V
            putstatic com.oracle.truffle.trufflenode.GraalJSAccess$NodeScriptOrModule.SCRIPT_OR_MODULE:Lcom/oracle/truffle/api/object/HiddenKey;
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  void <init>(com.oracle.truffle.js.runtime.JSContext, com.oracle.truffle.api.source.Source);
    descriptor: (Lcom/oracle/truffle/js/runtime/JSContext;Lcom/oracle/truffle/api/source/Source;)V
    flags: (0x0000) 
    Code:
      stack=3, locals=3, args_size=3
        start local 0 // com.oracle.truffle.trufflenode.GraalJSAccess$NodeScriptOrModule this
        start local 1 // com.oracle.truffle.js.runtime.JSContext context
        start local 2 // com.oracle.truffle.api.source.Source source
         0: .line 3605
            aload 0 /* this */
            aload 1 /* context */
            aload 2 /* source */
            invokespecial com.oracle.truffle.js.runtime.objects.ScriptOrModule.<init>:(Lcom/oracle/truffle/js/runtime/JSContext;Lcom/oracle/truffle/api/source/Source;)V
         1: .line 3606
            return
        end local 2 // com.oracle.truffle.api.source.Source source
        end local 1 // com.oracle.truffle.js.runtime.JSContext context
        end local 0 // com.oracle.truffle.trufflenode.GraalJSAccess$NodeScriptOrModule this
      LocalVariableTable:
        Start  End  Slot     Name  Signature
            0    2     0     this  Lcom/oracle/truffle/trufflenode/GraalJSAccess$NodeScriptOrModule;
            0    2     1  context  Lcom/oracle/truffle/js/runtime/JSContext;
            0    2     2   source  Lcom/oracle/truffle/api/source/Source;
    MethodParameters:
         Name  Flags
      context  
      source   

  java.util.Map<java.lang.Long, com.oracle.truffle.trufflenode.GraalJSAccess$WeakCallback> getWeakCallbackMap();
    descriptor: ()Ljava/util/Map;
    flags: (0x0000) 
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // com.oracle.truffle.trufflenode.GraalJSAccess$NodeScriptOrModule this
         0: .line 3609
            aload 0 /* this */
            getfield com.oracle.truffle.trufflenode.GraalJSAccess$NodeScriptOrModule.weakCallbackMap:Ljava/util/Map;
            ifnonnull 2
         1: .line 3610
            aload 0 /* this */
            new java.util.HashMap
            dup
            invokespecial java.util.HashMap.<init>:()V
            putfield com.oracle.truffle.trufflenode.GraalJSAccess$NodeScriptOrModule.weakCallbackMap:Ljava/util/Map;
         2: .line 3612
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield com.oracle.truffle.trufflenode.GraalJSAccess$NodeScriptOrModule.weakCallbackMap:Ljava/util/Map;
            areturn
        end local 0 // com.oracle.truffle.trufflenode.GraalJSAccess$NodeScriptOrModule this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lcom/oracle/truffle/trufflenode/GraalJSAccess$NodeScriptOrModule;
    Signature: ()Ljava/util/Map<Ljava/lang/Long;Lcom/oracle/truffle/trufflenode/GraalJSAccess$WeakCallback;>;
}
SourceFile: "GraalJSAccess.java"
NestHost: com.oracle.truffle.trufflenode.GraalJSAccess
InnerClasses:
  NodeScriptOrModule = com.oracle.truffle.trufflenode.GraalJSAccess$NodeScriptOrModule of com.oracle.truffle.trufflenode.GraalJSAccess
  private WeakCallback = com.oracle.truffle.trufflenode.GraalJSAccess$WeakCallback of com.oracle.truffle.trufflenode.GraalJSAccess