https://www.graalvm.org/ 
final class com.oracle.truffle.api.debug.SteppingStrategy$Unwind extends com.oracle.truffle.api.debug.SteppingStrategy
  minor version: 0
  major version: 59
  flags: flags: (0x0030) ACC_FINAL, ACC_SUPER
  this_class: com.oracle.truffle.api.debug.SteppingStrategy$Unwind
  super_class: com.oracle.truffle.api.debug.SteppingStrategy
{
  private final int depth;
    descriptor: I
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  private int stackCounter;
    descriptor: I
    flags: (0x0002) ACC_PRIVATE

  java.lang.ThreadDeath unwind;
    descriptor: Ljava/lang/ThreadDeath;
    flags: (0x0000) 

  void <init>(int);
    descriptor: (I)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
        start local 1 // int depth
         0: .line 537
            aload 0 /* this */
            invokespecial com.oracle.truffle.api.debug.SteppingStrategy.<init>:()V
         1: .line 538
            aload 0 /* this */
            iload 1 /* depth */
            ineg
            putfield com.oracle.truffle.api.debug.SteppingStrategy$Unwind.depth:I
         2: .line 539
            return
        end local 1 // int depth
        end local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    3     0   this  Lcom/oracle/truffle/api/debug/SteppingStrategy$Unwind;
            0    3     1  depth  I
    MethodParameters:
       Name  Flags
      depth  

  void initialize(com.oracle.truffle.api.debug.SuspendedContext, com.oracle.truffle.api.debug.SuspendAnchor);
    descriptor: (Lcom/oracle/truffle/api/debug/SuspendedContext;Lcom/oracle/truffle/api/debug/SuspendAnchor;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=3, args_size=3
        start local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
        start local 1 // com.oracle.truffle.api.debug.SuspendedContext contex
        start local 2 // com.oracle.truffle.api.debug.SuspendAnchor suspendAnchor
         0: .line 544
            aload 0 /* this */
            iconst_1
            putfield com.oracle.truffle.api.debug.SteppingStrategy$Unwind.stackCounter:I
         1: .line 545
            return
        end local 2 // com.oracle.truffle.api.debug.SuspendAnchor suspendAnchor
        end local 1 // com.oracle.truffle.api.debug.SuspendedContext contex
        end local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
      LocalVariableTable:
        Start  End  Slot           Name  Signature
            0    2     0           this  Lcom/oracle/truffle/api/debug/SteppingStrategy$Unwind;
            0    2     1         contex  Lcom/oracle/truffle/api/debug/SuspendedContext;
            0    2     2  suspendAnchor  Lcom/oracle/truffle/api/debug/SuspendAnchor;
    MethodParameters:
               Name  Flags
      contex         
      suspendAnchor  

  void notifyCallEntry();
    descriptor: ()V
    flags: (0x0000) 
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
         0: .line 549
            aload 0 /* this */
            dup
            getfield com.oracle.truffle.api.debug.SteppingStrategy$Unwind.stackCounter:I
            iconst_1
            iadd
            putfield com.oracle.truffle.api.debug.SteppingStrategy$Unwind.stackCounter:I
         1: .line 550
            return
        end local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lcom/oracle/truffle/api/debug/SteppingStrategy$Unwind;

  void notifyCallExit();
    descriptor: ()V
    flags: (0x0000) 
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
         0: .line 554
            aload 0 /* this */
            dup
            getfield com.oracle.truffle.api.debug.SteppingStrategy$Unwind.stackCounter:I
            iconst_1
            isub
            putfield com.oracle.truffle.api.debug.SteppingStrategy$Unwind.stackCounter:I
         1: .line 555
            return
        end local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lcom/oracle/truffle/api/debug/SteppingStrategy$Unwind;

  java.lang.Object notifyOnUnwind();
    descriptor: ()Ljava/lang/Object;
    flags: (0x0000) 
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
         0: .line 559
            aload 0 /* this */
            getfield com.oracle.truffle.api.debug.SteppingStrategy$Unwind.depth:I
            aload 0 /* this */
            getfield com.oracle.truffle.api.debug.SteppingStrategy$Unwind.stackCounter:I
            if_icmpne 2
         1: .line 560
            getstatic com.oracle.truffle.api.instrumentation.ProbeNode.UNWIND_ACTION_REENTER:Ljava/lang/Object;
            areturn
         2: .line 562
      StackMap locals:
      StackMap stack:
            aconst_null
            areturn
        end local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lcom/oracle/truffle/api/debug/SteppingStrategy$Unwind;

  boolean isActive(com.oracle.truffle.api.instrumentation.EventContext, com.oracle.truffle.api.debug.SuspendAnchor);
    descriptor: (Lcom/oracle/truffle/api/instrumentation/EventContext;Lcom/oracle/truffle/api/debug/SuspendAnchor;)Z
    flags: (0x0000) 
    Code:
      stack=2, locals=3, args_size=3
        start local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
        start local 1 // com.oracle.truffle.api.instrumentation.EventContext context
        start local 2 // com.oracle.truffle.api.debug.SuspendAnchor suspendAnchor
         0: .line 568
            getstatic com.oracle.truffle.api.debug.SuspendAnchor.BEFORE:Lcom/oracle/truffle/api/debug/SuspendAnchor;
            aload 2 /* suspendAnchor */
            if_acmpne 1
            iconst_1
            ireturn
      StackMap locals:
      StackMap stack:
         1: iconst_0
            ireturn
        end local 2 // com.oracle.truffle.api.debug.SuspendAnchor suspendAnchor
        end local 1 // com.oracle.truffle.api.instrumentation.EventContext context
        end local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
      LocalVariableTable:
        Start  End  Slot           Name  Signature
            0    2     0           this  Lcom/oracle/truffle/api/debug/SteppingStrategy$Unwind;
            0    2     1        context  Lcom/oracle/truffle/api/instrumentation/EventContext;
            0    2     2  suspendAnchor  Lcom/oracle/truffle/api/debug/SuspendAnchor;
    MethodParameters:
               Name  Flags
      context        
      suspendAnchor  

  boolean step(com.oracle.truffle.api.debug.DebuggerSession, com.oracle.truffle.api.instrumentation.EventContext, com.oracle.truffle.api.debug.SuspendAnchor);
    descriptor: (Lcom/oracle/truffle/api/debug/DebuggerSession;Lcom/oracle/truffle/api/instrumentation/EventContext;Lcom/oracle/truffle/api/debug/SuspendAnchor;)Z
    flags: (0x0000) 
    Code:
      stack=1, locals=4, args_size=4
        start local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
        start local 1 // com.oracle.truffle.api.debug.DebuggerSession steppingSession
        start local 2 // com.oracle.truffle.api.instrumentation.EventContext context
        start local 3 // com.oracle.truffle.api.debug.SuspendAnchor suspendAnchor
         0: .line 573
            iconst_1
            ireturn
        end local 3 // com.oracle.truffle.api.debug.SuspendAnchor suspendAnchor
        end local 2 // com.oracle.truffle.api.instrumentation.EventContext context
        end local 1 // com.oracle.truffle.api.debug.DebuggerSession steppingSession
        end local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
      LocalVariableTable:
        Start  End  Slot             Name  Signature
            0    1     0             this  Lcom/oracle/truffle/api/debug/SteppingStrategy$Unwind;
            0    1     1  steppingSession  Lcom/oracle/truffle/api/debug/DebuggerSession;
            0    1     2          context  Lcom/oracle/truffle/api/instrumentation/EventContext;
            0    1     3    suspendAnchor  Lcom/oracle/truffle/api/debug/SuspendAnchor;
    MethodParameters:
                 Name  Flags
      steppingSession  
      context          
      suspendAnchor    

  boolean isUnwind();
    descriptor: ()Z
    flags: (0x0000) 
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
         0: .line 578
            iconst_1
            ireturn
        end local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/api/debug/SteppingStrategy$Unwind;

  boolean isStopAfterCall();
    descriptor: ()Z
    flags: (0x0000) 
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
         0: .line 583
            iconst_0
            ireturn
        end local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/api/debug/SteppingStrategy$Unwind;

  public java.lang.String toString();
    descriptor: ()Ljava/lang/String;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=5, locals=1, args_size=1
        start local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
         0: .line 588
            ldc "REENTER(stackCounter=%s, depth=%s)"
            iconst_2
            anewarray java.lang.Object
            dup
            iconst_0
            aload 0 /* this */
            getfield com.oracle.truffle.api.debug.SteppingStrategy$Unwind.stackCounter:I
            invokestatic java.lang.Integer.valueOf:(I)Ljava/lang/Integer;
            aastore
            dup
            iconst_1
            aload 0 /* this */
            getfield com.oracle.truffle.api.debug.SteppingStrategy$Unwind.depth:I
            invokestatic java.lang.Integer.valueOf:(I)Ljava/lang/Integer;
            aastore
            invokestatic java.lang.String.format:(Ljava/lang/String;[Ljava/lang/Object;)Ljava/lang/String;
            areturn
        end local 0 // com.oracle.truffle.api.debug.SteppingStrategy$Unwind this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/api/debug/SteppingStrategy$Unwind;
}
SourceFile: "SteppingStrategy.java"
NestHost: com.oracle.truffle.api.debug.SteppingStrategy
InnerClasses:
  final Unwind = com.oracle.truffle.api.debug.SteppingStrategy$Unwind of com.oracle.truffle.api.debug.SteppingStrategy