code: def get_interfaces(self):
          
          LOG.debug("Getting interfaces from Xapi")
  
          with self.sessioned() as session:
              instances = self.get_instances(session)
              recs = session.xenapi.VIF.get_all_records()
  
          interfaces = set()
          for vif_ref, rec in recs.iteritems():
              vm = instances.get(rec["VM"])
              if not vm:
                  continue
              device_id = vm.uuid
              interfaces.add(VIF(device_id, rec, vif_ref))
          return interfaces
docs: Returns a set of VIFs from `get_instances` return value.