code: def extend(self, iterable):
          '''Extend this skiplist with an iterable over
          ``score``, ``value`` pairs.
          '''
          i = self.insert
          for score_values in iterable:
              i(*score_valuesf extend(self, iterable):
          '''Extend this skiplist with an iterable over
          ``score``, ``value`` pairs.
          '''
          i = self.insert
          for score_values in iterable:
              i(*score_values)
docs: Extend this skiplist with an iterable over
          ``score``, ``value`` pairs.