code: def linkify(self, hosts, timeperiods):
          
          self.linkify_hd_by_h(hosts)
          self.linkify_hd_by_tp(timeperiods)
          self.linkify_h_by_hd(hosts)
docs: Create link between objects::
  
           * hostdependency -> host
           * hostdependency -> timeperiods
  
          :param hosts: hosts to link
          :type hosts: alignak.objects.host.Hosts
          :param timeperiods: timeperiods to link
          :type timeperiods: alignak.objects.timeperiod.Timeperiods
          :return: None