def generate_corpus(self, text):
        """
        Given a text string, returns a list of lists; that is, a list of
        "sentences," each of which is a list of words. Before splitting into
        words, the sentences are filtered through `self.test_sentence_input`
        """
        if isinstance(text, str):
            sentences = self.sentence_split(text)
        else:
            sentences = []
            for line in text:
                sentences += self.sentence_split(line)
        passing = filter(self.test_sentence_input, sentences)
        runs = map(self.word_split, passing)
        return runs
Given a text string, returns a list of lists; that is, a list of
        "sentences," each of which is a list of words. Before splitting into
        words, the sentences are filtered through `self.test_sentence_input`