How to use the nlp.nlp_utils.get_sentences function in nlp

def build_text_manual(self, record):
        text = record[Constants.TEXT_FIELD]
        sentences = nlp_utils.get_sentences(text)
        lemmatized_words = []
        for sentence in sentences:
            lemmatized_words.append(nlp_utils.lemmatize_sentence(
                sentence, nltk.re.compile(''),
                min_length=1, max_length=100))

        doc_parts = []
        itemize = Itemize()

        for sentence in lemmatized_words:
            new_words = []
            itemize.add_item('')
            for tagged_word in sentence:
                tag = tagged_word[1]
                word = tagged_word[0]
                singular = pattern.text.en.singularize(word)