private ClassNode popWithMessage(int last) {
   try {
     return stack.remove(last);
   } catch (ArrayIndexOutOfBoundsException ai) {
     String method =
         controller.getMethodNode() == null
             ? controller.getConstructorNode().getTypeDescriptor()
             : controller.getMethodNode().getTypeDescriptor();
     throw new GroovyBugError(
         "Error while popping argument from operand stack tracker in class "
             + controller.getClassName()
             + " method "
             + method
             + ".");
   }
 }