mrb_class_defined_id(mrb_state *mrb, mrb_sym name)
{
  return mrb_const_defined(mrb, mrb_obj_value(mrb->object_class), name);
}
mrb_class_defined_id(mrb_state *mrb, mrb_sym name)
{
  return mrb_const_defined(mrb, mrb_obj_value(mrb->object_class), name);
}