code: def linkify_sd_by_tp(self, timeperiods):
          
          for servicedep in self:
              try:
                  tp_name = servicedep.dependency_period
                  timeperiod = timeperiods.find_by_name(tp_name)
                  if timeperiod:
                      servicedep.dependency_period = timeperiod.uuid
                  else:
                      servicedep.dependency_period = ''
              except AttributeError as exp:
                  logger.error("[servicedependency] fail to linkify by timeperiods: %s", exp)
docs: Replace dependency_period by a real object in service dependency
  
          :param timeperiods: list of timeperiod, used to look for a specific one
          :type timeperiods: alignak.objects.timeperiod.Timeperiods
          :return: None