code: def cumulative_statistics(self):
          
          if self._cumulative_statistics is None:
              self._cumulative_statistics = WorkersCumulativeStatisticsList(
                  self._version,
                  workspace_sid=self._solution['workspace_sid'],
              )
          return self._cumulative_statistics
docs: Access the cumulative_statistics
  
          :returns: twilio.rest.taskrouter.v1.workspace.worker.workers_cumulative_statistics.WorkersCumulativeStatisticsList
          :rtype: twilio.rest.taskrouter.v1.workspace.worker.workers_cumulative_statistics.WorkersCumulativeStatisticsList