https://www.graalvm.org/ 
public final class com.oracle.truffle.trufflenode.JSExternal extends com.oracle.truffle.js.runtime.builtins.JSNonProxy
  minor version: 0
  major version: 59
  flags: flags: (0x0031) ACC_PUBLIC, ACC_FINAL, ACC_SUPER
  this_class: com.oracle.truffle.trufflenode.JSExternal
  super_class: com.oracle.truffle.js.runtime.builtins.JSNonProxy
{
  public static final java.lang.String CLASS_NAME;
    descriptor: Ljava/lang/String;
    flags: (0x0019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL
    ConstantValue: "external"

  public static final com.oracle.truffle.trufflenode.JSExternal INSTANCE;
    descriptor: Lcom/oracle/truffle/trufflenode/JSExternal;
    flags: (0x0019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL

  static final boolean $assertionsDisabled;
    descriptor: Z
    flags: (0x1018) ACC_STATIC, ACC_FINAL, ACC_SYNTHETIC

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=2, locals=0, args_size=0
         0: .line 48
            ldc Lcom/oracle/truffle/trufflenode/JSExternal;
            invokevirtual java.lang.Class.desiredAssertionStatus:()Z
            ifne 1
            iconst_1
            goto 2
      StackMap locals:
      StackMap stack:
         1: iconst_0
      StackMap locals:
      StackMap stack: int
         2: putstatic com.oracle.truffle.trufflenode.JSExternal.$assertionsDisabled:Z
         3: .line 51
            new com.oracle.truffle.trufflenode.JSExternal
            dup
            invokespecial com.oracle.truffle.trufflenode.JSExternal.<init>:()V
            putstatic com.oracle.truffle.trufflenode.JSExternal.INSTANCE:Lcom/oracle/truffle/trufflenode/JSExternal;
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  private void <init>();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.oracle.truffle.trufflenode.JSExternal this
         0: .line 53
            aload 0 /* this */
            invokespecial com.oracle.truffle.js.runtime.builtins.JSNonProxy.<init>:()V
         1: .line 54
            return
        end local 0 // com.oracle.truffle.trufflenode.JSExternal this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lcom/oracle/truffle/trufflenode/JSExternal;

  public static com.oracle.truffle.api.object.DynamicObject create(com.oracle.truffle.js.runtime.JSContext, long);
    descriptor: (Lcom/oracle/truffle/js/runtime/JSContext;J)Lcom/oracle/truffle/api/object/DynamicObject;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=5, locals=5, args_size=2
        start local 0 // com.oracle.truffle.js.runtime.JSContext context
        start local 1 // long pointer
         0: .line 57
            aload 0 /* context */
            invokestatic com.oracle.truffle.trufflenode.GraalJSAccess.getContextEmbedderData:(Lcom/oracle/truffle/js/runtime/JSContext;)Lcom/oracle/truffle/trufflenode/ContextData;
            astore 3 /* contextData */
        start local 3 // com.oracle.truffle.trufflenode.ContextData contextData
         1: .line 58
            new com.oracle.truffle.trufflenode.JSExternalObject
            dup
            aload 3 /* contextData */
            invokevirtual com.oracle.truffle.trufflenode.ContextData.getExternalObjectShape:()Lcom/oracle/truffle/api/object/Shape;
            lload 1 /* pointer */
            invokespecial com.oracle.truffle.trufflenode.JSExternalObject.<init>:(Lcom/oracle/truffle/api/object/Shape;J)V
            astore 4 /* obj */
        start local 4 // com.oracle.truffle.api.object.DynamicObject obj
         2: .line 59
            getstatic com.oracle.truffle.trufflenode.JSExternal.$assertionsDisabled:Z
            ifne 3
            aload 4 /* obj */
            invokestatic com.oracle.truffle.trufflenode.JSExternal.isJSExternalObject:(Ljava/lang/Object;)Z
            ifne 3
            new java.lang.AssertionError
            dup
            invokespecial java.lang.AssertionError.<init>:()V
            athrow
         3: .line 60
      StackMap locals: com.oracle.truffle.trufflenode.ContextData com.oracle.truffle.api.object.DynamicObject
      StackMap stack:
            aload 4 /* obj */
            areturn
        end local 4 // com.oracle.truffle.api.object.DynamicObject obj
        end local 3 // com.oracle.truffle.trufflenode.ContextData contextData
        end local 1 // long pointer
        end local 0 // com.oracle.truffle.js.runtime.JSContext context
      LocalVariableTable:
        Start  End  Slot         Name  Signature
            0    4     0      context  Lcom/oracle/truffle/js/runtime/JSContext;
            0    4     1      pointer  J
            1    4     3  contextData  Lcom/oracle/truffle/trufflenode/ContextData;
            2    4     4          obj  Lcom/oracle/truffle/api/object/DynamicObject;
    MethodParameters:
         Name  Flags
      context  
      pointer  

  public static com.oracle.truffle.api.object.Shape makeInitialShape(com.oracle.truffle.js.runtime.JSContext);
    descriptor: (Lcom/oracle/truffle/js/runtime/JSContext;)Lcom/oracle/truffle/api/object/Shape;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // com.oracle.truffle.js.runtime.JSContext ctx
         0: .line 64
            aload 0 /* ctx */
            getstatic com.oracle.truffle.trufflenode.JSExternal.INSTANCE:Lcom/oracle/truffle/trufflenode/JSExternal;
            invokevirtual com.oracle.truffle.js.runtime.JSContext.makeEmptyShapeWithNullPrototype:(Lcom/oracle/truffle/js/runtime/builtins/JSClass;)Lcom/oracle/truffle/api/object/Shape;
            areturn
        end local 0 // com.oracle.truffle.js.runtime.JSContext ctx
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0   ctx  Lcom/oracle/truffle/js/runtime/JSContext;
    MethodParameters:
      Name  Flags
      ctx   

  public static boolean isJSExternalObject(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Z
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // java.lang.Object obj
         0: .line 68
            aload 0 /* obj */
            instanceof com.oracle.truffle.trufflenode.JSExternalObject
            ireturn
        end local 0 // java.lang.Object obj
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0   obj  Ljava/lang/Object;
    MethodParameters:
      Name  Flags
      obj   

  public java.lang.String getClassName(com.oracle.truffle.api.object.DynamicObject);
    descriptor: (Lcom/oracle/truffle/api/object/DynamicObject;)Ljava/lang/String;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=2, args_size=2
        start local 0 // com.oracle.truffle.trufflenode.JSExternal this
        start local 1 // com.oracle.truffle.api.object.DynamicObject object
         0: .line 73
            ldc "external"
            areturn
        end local 1 // com.oracle.truffle.api.object.DynamicObject object
        end local 0 // com.oracle.truffle.trufflenode.JSExternal this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    1     0    this  Lcom/oracle/truffle/trufflenode/JSExternal;
            0    1     1  object  Lcom/oracle/truffle/api/object/DynamicObject;
    MethodParameters:
        Name  Flags
      object  
}
SourceFile: "JSExternal.java"