docs: def clear_data(self):
          """Removes the content data.
  
          raise:  NoAccess - ``Metadata.isRequired()`` is ``true`` or
                  ``Metadata.isReadOnly()`` is ``true``
          *compliance: mandatory -- This method must be implemented.*
  
          """
          if (self.get_data_metadata().is_read_only() or
                  self.get_data_metadata().is_required()):
              raise errors.NoAccess()
          if self._my_map['data'] == self._data_default:
              return
          dbase = JSONClientValidated('repository',
                                      runtime=self._runtime).raw()
          filesys = gridfs.GridFS(dbase)
          filesys.delete(self._my_map['data'])
          self._my_map['data'] = self._data_default
          del self._my_map['base64']