def lemmatize(self):
_lemmatizer = PatternParserLemmatizer(tokenizer=NLTKPunktTokenizer())<EOL>_raw = "<STR_LIT:U+0020>".join(self) + "<STR_LIT:.>"<EOL>_lemmas = _lemmatizer.lemmatize(_raw)<EOL>return self.__class__([Word(l, t) for l, t in _lemmas])<EOL>
Return the lemma of each word in this WordList.

        Currently using NLTKPunktTokenizer() for all lemmatization
        tasks. This might cause slightly different tokenization results
        compared to the TextBlob.words property.