docs: def clear_n_of_m(self):
          """stub"""
          if (self.get_n_of_m_metadata().is_read_only() or
                  self.get_n_of_m_metadata().is_required()):
              raise NoAccess()
          self.my_osid_object_form._my_map['nOfM'] = \
              int(self._n_of_m_metadata['default_object_values'][0])