code: def add_children(self, frames, after=None):
          '''
          Convenience method to add multiple frames at once.
          '''
          if after is not None:
              # if there's an 'after' parameter, add the frames in reverse so the order is
              # preserved.
              for frame in reversed(frames):
                  self.add_child(frame, after=after)
          else:
              for frame in frames:
                  self.add_child(framef add_children(self, frames, after=None):
          '''
          Convenience method to add multiple frames at once.
          '''
          if after is not None:
              # if there's an 'after' parameter, add the frames in reverse so the order is
              # preserved.
              for frame in reversed(frames):
                  self.add_child(frame, after=after)
          else:
              for frame in frames:
                  self.add_child(frame)
docs: Convenience method to add multiple frames at once.