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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def authenticate(json_path=None):
 """Gets a Natural Language API parser by authenticating the API. **This method is deprecated.** Please use :obj:`budou.get_parser` to obtain a parser instead. Args: json_path (:obj:`str`, optional):
 The file path to the service account's credentials. Returns: Parser. (:obj:`budou.parser.NLAPIParser`) """

  msg = ('budou.authentication() is deprecated. '
         'Please use budou.get_parser() to obtain a parser instead.')
  warnings.warn(msg, DeprecationWarning)
  parser = get_parser('nlapi', credentials_path=json_path)
  return parser