code: def _sync_last_sale_prices(self, dt=None):
          
          if dt is None:
              dt = self.datetime
  
          if dt != self._last_sync_time:
              self.metrics_tracker.sync_last_sale_prices(
                  dt,
                  self.data_portal,
              )
              self._last_sync_time = dt
docs: Sync the last sale prices on the metrics tracker to a given
          datetime.
  
          Parameters
          ----------
          dt : datetime
              The time to sync the prices to.
  
          Notes
          -----
          This call is cached by the datetime. Repeated calls in the same bar
          are cheap.