def get_stoplisted_unigram_corpus_and_custom(self,
                                                 custom_stoplist):
        '''
        Parameters
        -------
        stoplist : list of lower-cased words, optional

        Returns
        -------
        A new TermDocumentMatrix consisting of only unigrams in the current TermDocumentMatrix.
        '''
        if type(custom_stoplist) == str:
            custom_stoplist = [custom_stoplist]
        return self._remove_terms_from_list(set(self.get_default_stoplist())
                                            | set(w.lower() for w in custom_stoplist))