code: def _serve_runs(self, request):
      if self._db_connection_provider:
        db = self._db_connection_provider()
        cursor = db.execute('''
          SELECT
            run_name,
            started_time IS NULL as started_time_nulls_last,
            started_time
          FROM Runs
          ORDER BY started_time_nulls_last, started_time, run_name
        ''')
        run_names = [row[0] for row in cursor]
      else:
        run_names = sorted(self._multiplexer.Runs())
        def get_first_event_timestamp(run_name):
          try:
            return self._multiplexer.FirstEventTimestamp(run_name)
          except ValueError as e:
            logger.warn(
                'Unable to get first event timestamp for run %s: %s', run_name, e)
            return float('inf')
        run_names.sort(key=get_first_event_timestamp)
      return http_util.Respond(request, run_names, 'application/json')