code: def _gen_uid(self):
          '''
          Generate the ID for post.
          :return: the new ID.
          '''
          cur_uid = self.kind + tools.get_uu4d()
          while MPost.get_by_uid(cur_uid):
              cur_uid = self.kind + tools.get_uu4d()
          return cur_uif _gen_uid(self):
          '''
          Generate the ID for post.
          :return: the new ID.
          '''
          cur_uid = self.kind + tools.get_uu4d()
          while MPost.get_by_uid(cur_uid):
              cur_uid = self.kind + tools.get_uu4d()
          return cur_uid
docs: Generate the ID for post.
          :return: the new ID.