code: def prune(self, minimum_word_frequency_percentage=1):
          
          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
docs: Filter out words that occur less than minimum_word_frequency times.
  
              :param minimum_word_frequency_percentage: minimum frequency of words to keep