Returns
        -------
        A new TermDocumentMatrix consisting of only terms which occur at least minimum_term_count.

def remove_infrequent_words(self, minimum_term_count, term_ranker=AbsoluteFrequencyRanker):
        '''
        Returns
        -------
        A new TermDocumentMatrix consisting of only terms which occur at least minimum_term_count.
        '''
        tdf = term_ranker(self).get_ranks().sum(axis=1)
        return self.remove_terms(list(tdf[tdf <= minimum_term_count].index))