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