docs: def addRemoteCandidate(self, candidate):
          """
          Add a remote candidate.
          """
          # FIXME: don't use private member!
          if not self._connection._remote_candidates_end:
              if candidate is None:
                  self._connection.add_remote_candidate(None)
              else:
                  self._connection.add_remote_candidate(candidate_to_aioice(candidate))