code: def filter_feed(self, updated=False, following=False, folder=False,
                      filter_folder="", sort="updated", nid=None):
          assert sum([updated, following, folder]) == 1
          if folder:
              assert filter_folder
          if updated:
              filter_type = dict(updated=1)
          elif following:
              filter_type = dict(following=1)
          else:
              filter_type = dict(folder=1, filter_folder=filter_folder)
          r = self.request(
              nid=nid,
              method="network.filter_feed",
              data=dict(
                  sort=sort,
                  **filter_type
              )
          )
          return self._handle_error(r, "Could not retrieve filtered feed.")