code: def get_usage(self, start=None, end=None):
          
          return self.manager.get_usage(self, start=start, end=end)
docs: Return the usage records for this load balancer. You may optionally
          include a start datetime or an end datetime, or both, which will limit
          the records to those on or after the start time, and those before or on
          the end time. These times should be Python datetime.datetime objects,
          Python datetime.date objects, or strings in the format:
          "YYYY-MM-DD HH:MM:SS" or "YYYY-MM-DD".