code: def _flag_is_registered(self, flag_obj):
      
      flag_dict = self._flags()
      # Check whether flag_obj is registered under its long name.
      name = flag_obj.name
      if flag_dict.get(name, None) == flag_obj:
        return True
      # Check whether flag_obj is registered under its short name.
      short_name = flag_obj.short_name
      if (short_name is not None and
          flag_dict.get(short_name, None) == flag_obj):
        return True
      return False
docs: Checks whether a Flag object is registered under long name or short name.
  
      Args:
        flag_obj: Flag, the Flag instance to check for.
  
      Returns:
        bool, True iff flag_obj is registered under long name or short name.