code: def get_cursor_time(self, project_name, logstore_name, shard_id, cursor):
          
  
          headers = {'Content-Type': 'application/json'}
          params = {'type': 'cursor_time', 'cursor': cursor}
          resource = "/logstores/" + logstore_name + "/shards/" + str(shard_id)
  
          (resp, header) = self._send("GET", project_name, None, resource, params, headers)
          return GetCursorTimeResponse(resp, header)
docs: Get cursor time from log service
          Unsuccessful opertaion will cause an LogException.
  
          :type project_name: string
          :param project_name: the Project name 
  
          :type logstore_name: string
          :param logstore_name: the logstore name
  
          :type shard_id: int
          :param shard_id: the shard id
  
          :type cursor: string
          :param cursor: the cursor to get its service receive time
  
          :return: GetCursorTimeResponse
  
          :raise: LogException