https://www.graalvm.org/ 
class com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr implements java.util.Iterator<java.util.List<com.oracle.truffle.api.debug.DebugStackTraceElement>>
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr
  super_class: java.lang.Object
{
  int cursor;
    descriptor: I
    flags: (0x0000) 

  final com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists this$1;
    descriptor: Lcom/oracle/truffle/api/debug/SuspendedEvent$DebugAsyncStackFrameLists;
    flags: (0x1010) ACC_FINAL, ACC_SYNTHETIC

  private void <init>(com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists);
    descriptor: (Lcom/oracle/truffle/api/debug/SuspendedEvent$DebugAsyncStackFrameLists;)V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr this
         0: .line 1016
            aload 0 /* this */
            aload 1
            putfield com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr.this$1:Lcom/oracle/truffle/api/debug/SuspendedEvent$DebugAsyncStackFrameLists;
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 1017
            aload 0 /* this */
            iconst_0
            putfield com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr.cursor:I
         2: .line 1016
            return
        end local 0 // com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lcom/oracle/truffle/api/debug/SuspendedEvent$DebugAsyncStackFrameLists$Itr;
    MethodParameters:
        Name  Flags
      this$0  final

  public boolean hasNext();
    descriptor: ()Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr this
         0: .line 1021
            aload 0 /* this */
            getfield com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr.this$1:Lcom/oracle/truffle/api/debug/SuspendedEvent$DebugAsyncStackFrameLists;
            aload 0 /* this */
            getfield com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr.cursor:I
            invokevirtual com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists.fillStacks:(I)I
            aload 0 /* this */
            getfield com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr.cursor:I
            if_icmpne 1
            iconst_1
            ireturn
      StackMap locals:
      StackMap stack:
         1: iconst_0
            ireturn
        end local 0 // com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lcom/oracle/truffle/api/debug/SuspendedEvent$DebugAsyncStackFrameLists$Itr;

  public java.util.List<com.oracle.truffle.api.debug.DebugStackTraceElement> next();
    descriptor: ()Ljava/util/List;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=1
        start local 0 // com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr this
         0: .line 1027
            aload 0 /* this */
            getfield com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr.cursor:I
            istore 1 /* i */
        start local 1 // int i
         1: .line 1028
            aload 0 /* this */
            getfield com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr.this$1:Lcom/oracle/truffle/api/debug/SuspendedEvent$DebugAsyncStackFrameLists;
            iload 1 /* i */
            invokevirtual com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists.get:(I)Ljava/util/List;
            astore 2 /* next */
        start local 2 // java.util.List next
         2: .line 1029
            aload 0 /* this */
            iload 1 /* i */
            iconst_1
            iadd
            putfield com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr.cursor:I
         3: .line 1030
            aload 2 /* next */
         4: areturn
        end local 2 // java.util.List next
        end local 1 // int i
         5: .line 1031
      StackMap locals:
      StackMap stack: java.lang.IndexOutOfBoundsException
            pop
         6: .line 1032
            new java.util.NoSuchElementException
            dup
            invokespecial java.util.NoSuchElementException.<init>:()V
            athrow
        end local 0 // com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    7     0  this  Lcom/oracle/truffle/api/debug/SuspendedEvent$DebugAsyncStackFrameLists$Itr;
            1    5     1     i  I
            2    5     2  next  Ljava/util/List<Lcom/oracle/truffle/api/debug/DebugStackTraceElement;>;
      Exception table:
        from    to  target  type
           0     4       5  Class java.lang.IndexOutOfBoundsException
    Signature: ()Ljava/util/List<Lcom/oracle/truffle/api/debug/DebugStackTraceElement;>;

  public void remove();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr this
         0: .line 1038
            new java.lang.UnsupportedOperationException
            dup
            invokespecial java.lang.UnsupportedOperationException.<init>:()V
            athrow
        end local 0 // com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/api/debug/SuspendedEvent$DebugAsyncStackFrameLists$Itr;

  public java.lang.Object next();
    descriptor: ()Ljava/lang/Object;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=1, locals=1, args_size=1
         0: .line 1
            aload 0
            invokevirtual com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr.next:()Ljava/util/List;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
}
Signature: Ljava/lang/Object;Ljava/util/Iterator<Ljava/util/List<Lcom/oracle/truffle/api/debug/DebugStackTraceElement;>;>;
SourceFile: "SuspendedEvent.java"
NestHost: com.oracle.truffle.api.debug.SuspendedEvent
InnerClasses:
  final DebugAsyncStackFrameLists = com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists of com.oracle.truffle.api.debug.SuspendedEvent
  private Itr = com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists$Itr of com.oracle.truffle.api.debug.SuspendedEvent$DebugAsyncStackFrameLists