https://www.graalvm.org/ 
class com.oracle.truffle.api.debug.Debugger$1 implements com.oracle.truffle.api.debug.impl.DebuggerInstrument$DebuggerFactory
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.oracle.truffle.api.debug.Debugger$1
  super_class: java.lang.Object
{
  void <init>();
    descriptor: ()V
    flags: (0x0000) 
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.oracle.truffle.api.debug.Debugger$1 this
         0: .line 374
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // com.oracle.truffle.api.debug.Debugger$1 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/api/debug/Debugger$1;

  public com.oracle.truffle.api.debug.Debugger create(com.oracle.truffle.api.instrumentation.TruffleInstrument$Env);
    descriptor: (Lcom/oracle/truffle/api/instrumentation/TruffleInstrument$Env;)Lcom/oracle/truffle/api/debug/Debugger;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // com.oracle.truffle.api.debug.Debugger$1 this
        start local 1 // com.oracle.truffle.api.instrumentation.TruffleInstrument$Env env
         0: .line 376
            new com.oracle.truffle.api.debug.Debugger
            dup
            aload 1 /* env */
            invokespecial com.oracle.truffle.api.debug.Debugger.<init>:(Lcom/oracle/truffle/api/instrumentation/TruffleInstrument$Env;)V
            areturn
        end local 1 // com.oracle.truffle.api.instrumentation.TruffleInstrument$Env env
        end local 0 // com.oracle.truffle.api.debug.Debugger$1 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/api/debug/Debugger$1;
            0    1     1   env  Lcom/oracle/truffle/api/instrumentation/TruffleInstrument$Env;
    MethodParameters:
      Name  Flags
      env   
}
SourceFile: "Debugger.java"
EnclosingMethod: com.oracle.truffle.api.debug.Debugger
NestHost: com.oracle.truffle.api.debug.Debugger
InnerClasses:
  com.oracle.truffle.api.debug.Debugger$1
  public abstract DebuggerFactory = com.oracle.truffle.api.debug.impl.DebuggerInstrument$DebuggerFactory of com.oracle.truffle.api.debug.impl.DebuggerInstrument
  public final Env = com.oracle.truffle.api.instrumentation.TruffleInstrument$Env of com.oracle.truffle.api.instrumentation.TruffleInstrument