https://www.graalvm.org/ 
public final class com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample extends com.oracle.truffle.api.instrumentation.TruffleInstrument
  minor version: 0
  major version: 59
  flags: flags: (0x0031) ACC_PUBLIC, ACC_FINAL, ACC_SUPER
  this_class: com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample
  super_class: com.oracle.truffle.api.instrumentation.TruffleInstrument
{
  private com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample$Controller controller;
    descriptor: Lcom/oracle/truffle/api/instrumentation/test/examples/DebuggerExample$Controller;
    flags: (0x0002) ACC_PRIVATE

  public static final java.lang.String ID;
    descriptor: Ljava/lang/String;
    flags: (0x0019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL
    ConstantValue: "example-debugger"

  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=1, locals=0, args_size=0
         0: .line 66
            ldc Lcom/oracle/truffle/api/instrumentation/test/examples/DebuggerExample;
            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.api.instrumentation.test.examples.DebuggerExample.$assertionsDisabled:Z
         3: .line 258
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample this
         0: .line 66
            aload 0 /* this */
            invokespecial com.oracle.truffle.api.instrumentation.TruffleInstrument.<init>:()V
            return
        end local 0 // com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/api/instrumentation/test/examples/DebuggerExample;

  protected void onCreate(com.oracle.truffle.api.instrumentation.TruffleInstrument$Env);
    descriptor: (Lcom/oracle/truffle/api/instrumentation/TruffleInstrument$Env;)V
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=4, locals=2, args_size=2
        start local 0 // com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample this
        start local 1 // com.oracle.truffle.api.instrumentation.TruffleInstrument$Env env
         0: .line 71
            getstatic com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample.$assertionsDisabled:Z
            ifne 1
            aload 0 /* this */
            getfield com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample.controller:Lcom/oracle/truffle/api/instrumentation/test/examples/DebuggerExample$Controller;
            ifnull 1
            new java.lang.AssertionError
            dup
            invokespecial java.lang.AssertionError.<init>:()V
            athrow
         1: .line 72
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            new com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample$Controller
            dup
            aload 1 /* env */
            invokevirtual com.oracle.truffle.api.instrumentation.TruffleInstrument$Env.getInstrumenter:()Lcom/oracle/truffle/api/instrumentation/Instrumenter;
            invokespecial com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample$Controller.<init>:(Lcom/oracle/truffle/api/instrumentation/Instrumenter;)V
            putfield com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample.controller:Lcom/oracle/truffle/api/instrumentation/test/examples/DebuggerExample$Controller;
         2: .line 73
            aload 1 /* env */
            aload 0 /* this */
            getfield com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample.controller:Lcom/oracle/truffle/api/instrumentation/test/examples/DebuggerExample$Controller;
            invokevirtual com.oracle.truffle.api.instrumentation.TruffleInstrument$Env.registerService:(Ljava/lang/Object;)V
         3: .line 74
            return
        end local 1 // com.oracle.truffle.api.instrumentation.TruffleInstrument$Env env
        end local 0 // com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    4     0  this  Lcom/oracle/truffle/api/instrumentation/test/examples/DebuggerExample;
            0    4     1   env  Lcom/oracle/truffle/api/instrumentation/TruffleInstrument$Env;
    MethodParameters:
      Name  Flags
      env   

  protected void onDispose(com.oracle.truffle.api.instrumentation.TruffleInstrument$Env);
    descriptor: (Lcom/oracle/truffle/api/instrumentation/TruffleInstrument$Env;)V
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=0, locals=2, args_size=2
        start local 0 // com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample this
        start local 1 // com.oracle.truffle.api.instrumentation.TruffleInstrument$Env env
         0: .line 256
            return
        end local 1 // com.oracle.truffle.api.instrumentation.TruffleInstrument$Env env
        end local 0 // com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/api/instrumentation/test/examples/DebuggerExample;
            0    1     1   env  Lcom/oracle/truffle/api/instrumentation/TruffleInstrument$Env;
    MethodParameters:
      Name  Flags
      env   
}
SourceFile: "DebuggerExample.java"
NestMembers:
  com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample$Controller  com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample$Controller$1  com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample$Controller$Breakpoint  com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample$Controller$StepCallBack  com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample$Controller$StepIntoCallback  com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample$Controller$StepOutCallback  com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample$Controller$StepOverCallback  com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample$Controller$Stepping
InnerClasses:
  public final Env = com.oracle.truffle.api.instrumentation.TruffleInstrument$Env of com.oracle.truffle.api.instrumentation.TruffleInstrument
  public abstract Registration = com.oracle.truffle.api.instrumentation.TruffleInstrument$Registration of com.oracle.truffle.api.instrumentation.TruffleInstrument
  private final Controller = com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample$Controller of com.oracle.truffle.api.instrumentation.test.examples.DebuggerExample
    RuntimeVisibleAnnotations: 
      com.oracle.truffle.api.instrumentation.TruffleInstrument$Registration(id = "example-debugger", services = {Lcom/oracle/truffle/api/instrumentation/test/examples/DebuggerController;})