docs: def set_identifiers(self, data):
          """
          Sets the identifier(s) within the instance data.
  
          The identifier name(s) is/are determined from the ``ResourceDetails``
          instance hanging off the class itself.
  
          :param data: The value(s) to be set.
          :param data: dict
          """
          for id_info in self._details.identifiers:
              var_name = id_info['var_name']
              self._data[var_name] = data.get(var_name)
  
          # FIXME: This needs to likely kick off invalidating/rebuilding
          #        relations.
          #        For now, just remove them all. This is potentially inefficient
          #        but is nicely lazy if we don't need them & prevents stale data
          #        for the moment.
          self._relations = {}