code: def add_context(self, isc_name, isc_policy_id, isc_traffic_tag):
          
          if 'add_context' in self.data.links: # SMC >=6.5
              element = ElementCreator(
                  VSSContext,
                  href=self.get_relation('add_context'),
                  json = {
                      'name': isc_name,
                      'vc_isc': {
                          'isc_name': isc_name,
                          'isc_policy_id': isc_policy_id,
                          'isc_traffic_tag': isc_traffic_tag
                      }
                  })
          else: # SMC < 6.5
              element = VSSContext.create(
                  isc_name=isc_name,
                  isc_policy_id=isc_policy_id,
                  isc_traffic_tag=isc_traffic_tag,
                  vss_container=self)
          
          # Delete cache since the virtualResources node is attached to
          # the engine json
          self._del_cache()
          return element
docs: Create the VSS Context within the VSSContainer
  
          :param str isc_name: ISC name, possibly append policy name??
          :param str isc_policy_id: Policy ID in SMC (the 'key' attribute)
          :param str isc_traffic_tag: NSX groupId (serviceprofile-145)
          :raises CreateElementFailed: failed to create
          :return: VSSContext