code: def drop_right_t(n):
      
      if n <= 0:
          end_index = None
      else:
          end_index = -n
      return Transformation(
          'drop_right({0})'.format(n),
          lambda sequence: sequence[:end_index],
          None
      )
docs: Transformation for Sequence.drop_right
      :param n: number to drop from right
      :return: transformation