code: def transform(self, input_: list) -> list:
      """
      Lemmatization a sequence of tokens.
  
      :param input_: list of tokens to be lemmatized.
  
      :return tokens: list of lemmatizd tokens.
      """
      lemmatizer = nltk.WordNetLemmatizer()
      return [lemmatizer.lemmatize(token, pos="v") for token in input_]
  
imports: import nltk
  from .unit import Unit
label_desc: Use image node_id 1 for calling the Lemmatization obj's underlying member method code with example usage: obj.transform(input_) and returns: unknown