code: def update(self, iterable):
          
          if isinstance(iterable, RangeSet):
              # keep padding unless is has not been defined yet
              if self.padding is None and iterable.padding is not None:
                  self.padding = iterable.padding
          assert type(iterable) is not str
          set.update(self, iterable)
docs: Add all integers from an iterable (such as a list).