code: def get_window_by_index(self, index):
          " Return the Window with this index or None if not found. "
          for w in self.windows:
              if w.index == index:
                  return f get_window_by_index(self, index):
          " Return the Window with this index or None if not found. "
          for w in self.windows:
              if w.index == index:
                  return w
docs: Return the Window with this index or None if not found.