https://www.graalvm.org/ 
class com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2 implements java.lang.Runnable
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2
  super_class: java.lang.Object
{
  final com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest this$0;
    descriptor: Lcom/oracle/truffle/api/instrumentation/test/InstrumentationMultiThreadingTest;
    flags: (0x1010) ACC_FINAL, ACC_SYNTHETIC

  private final java.util.concurrent.atomic.AtomicBoolean val$terminated;
    descriptor: Ljava/util/concurrent/atomic/AtomicBoolean;
    flags: (0x1012) ACC_PRIVATE, ACC_FINAL, ACC_SYNTHETIC

  private final java.util.concurrent.atomic.AtomicReference val$engineRef;
    descriptor: Ljava/util/concurrent/atomic/AtomicReference;
    flags: (0x1012) ACC_PRIVATE, ACC_FINAL, ACC_SYNTHETIC

  private final int val$index;
    descriptor: I
    flags: (0x1012) ACC_PRIVATE, ACC_FINAL, ACC_SYNTHETIC

  void <init>(com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest, java.util.concurrent.atomic.AtomicBoolean, java.util.concurrent.atomic.AtomicReference, int);
    descriptor: (Lcom/oracle/truffle/api/instrumentation/test/InstrumentationMultiThreadingTest;Ljava/util/concurrent/atomic/AtomicBoolean;Ljava/util/concurrent/atomic/AtomicReference;I)V
    flags: (0x0000) 
    Code:
      stack=2, locals=5, args_size=5
        start local 0 // com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2 this
         0: .line 107
            aload 0 /* this */
            aload 1
            putfield com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2.this$0:Lcom/oracle/truffle/api/instrumentation/test/InstrumentationMultiThreadingTest;
            aload 0 /* this */
            aload 2
            putfield com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2.val$terminated:Ljava/util/concurrent/atomic/AtomicBoolean;
            aload 0 /* this */
            aload 3
            putfield com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2.val$engineRef:Ljava/util/concurrent/atomic/AtomicReference;
            aload 0 /* this */
            iload 4
            putfield com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2.val$index:I
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/api/instrumentation/test/InstrumentationMultiThreadingTest$2;
    MethodParameters:
                Name  Flags
      this$0          final
      val$terminated  final
      val$engineRef   final
      val$index       final

  public void run();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=2, args_size=1
        start local 0 // com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2 this
         0: .line 109
            goto 9
         1: .line 110
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2.val$engineRef:Ljava/util/concurrent/atomic/AtomicReference;
            invokevirtual java.util.concurrent.atomic.AtomicReference.get:()Ljava/lang/Object;
            checkcast org.graalvm.polyglot.Context
            astore 1 /* engine */
        start local 1 // org.graalvm.polyglot.Context engine
         2: .line 111
            aload 1 /* engine */
            ifnull 9
         3: .line 112
            aload 1 /* engine */
            invokevirtual org.graalvm.polyglot.Context.getEngine:()Lorg/graalvm/polyglot/Engine;
            invokevirtual org.graalvm.polyglot.Engine.getInstruments:()Ljava/util/Map;
            ldc "testAsyncAttachement1"
            invokeinterface java.util.Map.get:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast org.graalvm.polyglot.Instrument
            ldc Lcom/oracle/truffle/api/instrumentation/test/EnableableInstrument;
            invokevirtual org.graalvm.polyglot.Instrument.lookup:(Ljava/lang/Class;)Ljava/lang/Object;
            checkcast com.oracle.truffle.api.instrumentation.test.EnableableInstrument
            aload 0 /* this */
            getfield com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2.val$index:I
            iconst_2
            irem
            ifne 4
            iconst_1
            goto 5
      StackMap locals: com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2 org.graalvm.polyglot.Context
      StackMap stack: com.oracle.truffle.api.instrumentation.test.EnableableInstrument
         4: iconst_0
      StackMap locals: com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2 org.graalvm.polyglot.Context
      StackMap stack: com.oracle.truffle.api.instrumentation.test.EnableableInstrument int
         5: invokevirtual com.oracle.truffle.api.instrumentation.test.EnableableInstrument.setEnabled:(Z)V
         6: .line 113
            aload 1 /* engine */
            invokevirtual org.graalvm.polyglot.Context.getEngine:()Lorg/graalvm/polyglot/Engine;
            invokevirtual org.graalvm.polyglot.Engine.getInstruments:()Ljava/util/Map;
            ldc "testAsyncAttachement2"
            invokeinterface java.util.Map.get:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast org.graalvm.polyglot.Instrument
            ldc Lcom/oracle/truffle/api/instrumentation/test/EnableableInstrument;
            invokevirtual org.graalvm.polyglot.Instrument.lookup:(Ljava/lang/Class;)Ljava/lang/Object;
            checkcast com.oracle.truffle.api.instrumentation.test.EnableableInstrument
            aload 0 /* this */
            getfield com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2.val$index:I
            iconst_2
            irem
            iconst_1
            if_icmpne 7
            iconst_1
            goto 8
      StackMap locals:
      StackMap stack: com.oracle.truffle.api.instrumentation.test.EnableableInstrument
         7: iconst_0
      StackMap locals: com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2 org.graalvm.polyglot.Context
      StackMap stack: com.oracle.truffle.api.instrumentation.test.EnableableInstrument int
         8: invokevirtual com.oracle.truffle.api.instrumentation.test.EnableableInstrument.setEnabled:(Z)V
        end local 1 // org.graalvm.polyglot.Context engine
         9: .line 109
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2.val$terminated:Ljava/util/concurrent/atomic/AtomicBoolean;
            invokevirtual java.util.concurrent.atomic.AtomicBoolean.get:()Z
            ifeq 1
        10: .line 116
            return
        end local 0 // com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2 this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0   11     0    this  Lcom/oracle/truffle/api/instrumentation/test/InstrumentationMultiThreadingTest$2;
            2    9     1  engine  Lorg/graalvm/polyglot/Context;
}
SourceFile: "InstrumentationMultiThreadingTest.java"
EnclosingMethod: com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest.testAsyncAttachement:()V
NestHost: com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest
InnerClasses:
  com.oracle.truffle.api.instrumentation.test.InstrumentationMultiThreadingTest$2