class_docstr: Raised when attempting to register a subclass which is already
  registered
code: def __init__(self, name, new_class, existing_class):
      msg = (
          "Cannot register %s for %s as it has already been used to "
          "register %s"
          % (name, new_class.__name__, existing_class.__name__)
      )
      super(AlreadyRegisteredError, self).__init__(msg)
  
imports: from snips_nlu.__about__ import __model_version__
label_desc: Use image node_id 1 to create a new AlreadyRegisteredError object from inherited base classes: SnipsNLUError with example: obj = AlreadyRegisteredError(name, new_class, existing_class)