code: def explode_services_from_templates(self, hosts, service_template):
          
          hname = getattr(service_template, "host_name", None)
          if not hname:
              logger.debug("Service template %s is declared without an host_name",
                           service_template.get_name())
              return
  
          logger.debug("Explode services %s for the host: %s", service_template.get_name(), hname)
  
          # Now really create the services
          if is_complex_expr(hname):
              hnames = self.evaluate_hostgroup_expression(
                  hname.strip(), hosts, hosts.templates, look_in='templates')
              for name in hnames:
                  self._local_create_service(hosts, name, service_template)
          else:
              hnames = [n.strip() for n in hname.split(',') if n.strip()]
              for hname in hnames:
                  for name in hosts.find_hosts_that_use_template(hname):
                      self._local_create_service(hosts, name, service_template)
docs: Explodes services from templates. All hosts holding the specified
          templates are bound with the service.
  
          :param hosts: The hosts container.
          :type hosts: alignak.objects.host.Hosts
          :param service_template: The service to explode.
          :type service_template: alignak.objects.service.Service
          :return: None