Filter out words that occur less than minimum_word_frequency times.

            :param minimum_word_frequency_percentage: minimum frequency of words to keep

def prune(self, minimum_word_frequency_percentage=1):
        """
        Filter out words that occur less than minimum_word_frequency times.

            :param minimum_word_frequency_percentage: minimum frequency of words to keep
        """
        pruned_resulting_documents = []

        for document in self.resulting_documents:
            new_document = []
            for word in document:
                if self.word_in_how_many_documents[word] >= minimum_word_frequency_percentage / 100. * len(
                        self.resulting_documents):
                    new_document.append(word)
            pruned_resulting_documents.append(new_document)
        self.resulting_documents = pruned_resulting_documents