code: def find_time_base(self, gps, first_us_stamp):
          '''work out time basis for the log - even newer style'''
          t = self._gpsTimeToTime(gps.GWk, gps.GMS)
          self.set_timebase(t - gps.TimeUS*0.000001)
          # this ensures FMT messages get appropriate timestamp:
          self.timestamp = self.timebase + first_us_stamp*0.00000f find_time_base(self, gps, first_us_stamp):
          '''work out time basis for the log - even newer style'''
          t = self._gpsTimeToTime(gps.GWk, gps.GMS)
          self.set_timebase(t - gps.TimeUS*0.000001)
          # this ensures FMT messages get appropriate timestamp:
          self.timestamp = self.timebase + first_us_stamp*0.000001
docs: work out time basis for the log - even newer style