code: def set(self, context, value, **kwargs):
          
          if self.multiValued:
              if not value:
                  value = []
              if type(value) not in (list, tuple):
                  value = [value, ]
              ret = [self.get_object(context, val) for val in value if val]
              self._set_backreferences(context, ret, **kwargs)
              uids = [self.get_uid(context, r) for r in ret if r]
              StringField.set(self, context, uids, **kwargs)
          else:
              # Sometimes we get given a list here with an empty string.
              # This is generated by html forms with empty values.
              # This is a single-valued field though, so:
              if isinstance(value, list) and value:
                  if len(value) > 1:
                      logger.warning(
                          "Found values '\'{}\'' for singleValued field <{}>.{} "
                          "- using only the first value in the list.".format(
                              '\',\''.join(value), context.UID(), self.getName()))
                  value = value[0]
              ret = self.get_object(context, value)
              if ret:
                  self._set_backreferences(context, [ret, ], **kwargs)
                  uid = self.get_uid(context, ret)
                  StringField.set(self, context, uid, **kwargs)
              else:
                  StringField.set(self, context, '', **kwargs)
docs: Accepts a UID, brain, or an object (or a list of any of these),
          and stores a UID or list of UIDS.
  
          :param context: context is the object who's schema contains this field.
          :type context: BaseContent
          :param value: A UID, brain or object (or a sequence of these).
          :type value: Any
          :param kwargs: kwargs are passed directly to the underlying get.
          :type kwargs: dict
          :return: None