code: def transform(self, input_: list) -> list:
      """
      Convert list of tokens to lower case.
  
      :param input_: list of tokens.
  
      :return tokens: lower-cased list of tokens.
      """
      return [token.lower() for token in input_]
  
label_desc: Use image node_id 1 for calling the Lowercase obj's underlying member method code with example usage: obj.transform(input_) and returns: unknown