code: def calibration_cache_path(self):
      
      if self.__ifo and self.__start > 0:
          cal_path = self.job().get_config('calibration','path')
  
          # check if this is S2: split calibration epochs
          if ( self.__LHO2k.match(self.__ifo) and
            (self.__start >= 729273613) and (self.__start <= 734367613) ):
            if self.__start < int(
              self.job().get_config('calibration','H2-cal-epoch-boundary')):
              cal_file = self.job().get_config('calibration','H2-1')
            else:
              cal_file = self.job().get_config('calibration','H2-2')
          else:
              # if not: just add calibration cache
              cal_file = self.job().get_config('calibration',self.__ifo)
  
          cal = os.path.join(cal_path,cal_file)
          self.__calibration_cache = cal
      else:
         msg = "IFO and start-time must be set first"
         raise CondorDAGNodeError, msg
docs: Determine the path to the correct calibration cache file to use.