code: def list(cls, vrf=None):
          
  
          if vrf is None:
              vrf = {}
  
          xmlrpc = XMLRPCConnection()
          try:
              vrf_list = xmlrpc.connection.list_vrf(
                  {
                      'vrf': vrf,
                      'auth': AuthOptions().options
                  })
          except xmlrpclib.Fault as xml_fault:
              raise _fault_to_exception(xml_fault)
  
          res = list()
          for v in vrf_list:
              res.append(VRF.from_dict(v))
  
          return res
docs: List VRFs.
  
              Maps to the function :py:func:`nipap.backend.Nipap.list_vrf` in the
              backend. Please see the documentation for the backend function for
              information regarding input arguments and return values.