code: def render(self, ctx=None):
          '''
          :param ctx: rendering context in which the method was called
          :rtype: `Bits`
          :return: rendered value of the container, padded if needed
          '''
          super(Pad, self).render(ctx)
          self.set_current_value(self._pad_buffer(self._current_rendered))
          return self._current_renderef render(self, ctx=None):
          '''
          :param ctx: rendering context in which the method was called
          :rtype: `Bits`
          :return: rendered value of the container, padded if needed
          '''
          super(Pad, self).render(ctx)
          self.set_current_value(self._pad_buffer(self._current_rendered))
          return self._current_rendered
docs: :param ctx: rendering context in which the method was called
          :rtype: `Bits`
          :return: rendered value of the container, padded if needed