code: def get_work_items_batch(self, work_item_get_request, project=None):
          
          route_values = {}
          if project is not None:
              route_values['project'] = self._serialize.url('project', project, 'str')
          content = self._serialize.body(work_item_get_request, 'WorkItemBatchGetRequest')
          response = self._send(http_method='POST',
                                location_id='908509b6-4248-4475-a1cd-829139ba419f',
                                version='5.0',
                                route_values=route_values,
                                content=content)
          return self._deserialize('[WorkItem]', self._unwrap_collection(response))
docs: GetWorkItemsBatch.
          Gets work items for a list of work item ids (Maximum 200)
          :param :class:`<WorkItemBatchGetRequest> <azure.devops.v5_0.work_item_tracking.models.WorkItemBatchGetRequest>` work_item_get_request:
          :param str project: Project ID or project name
          :rtype: [WorkItem]