text: #!/usr/bin/env python
  # -*- coding: utf-8 -*--
  
  # Copyright (c) 2021 Oracle and/or its affiliates.
  # Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl/
  
  """
  The module that represents an Unknown feature type.
  
  Classes:
      Text
          The Unknown feature type.
  """
  from ads.feature_engineering.feature_type.base import FeatureType
  
  
  class Unknown(FeatureType):
      """
      Type representing third-party dtypes.
  
      Attributes
      ----------
      description: str
          The feature type description.
      name: str
          The feature type name.
      warning: FeatureWarning
          Provides functionality to register warnings and invoke them.
      validator
          Provides functionality to register validators and invoke them.
      """
  
      description = "Type representing unknown type."
  
      @classmethod
      def feature_domain(cls):
          """
          Returns
          -------
          None
              Nothing.
          """
          return None
  