def METHOD_NAME(self, method, params):
  if not self.cctbx_interface.enable_xmlrpc :
    return -1
  result = -1
  func = getattr(self.cctbx_interface, method, None)
  if not callable(func):
    print("%s is not a callable object!" % method)
  else :
    result = func(*params)
    if result is None :
      result = -1
  return result