code: def sliding_t(wrap, size, step):
      
      return Transformation(
          'sliding({0}, {1})'.format(size, step),
          partial(sliding_impl, wrap, size, step),
          {ExecutionStrategies.PRE_COMPUTE}
      )
docs: Transformation for Sequence.sliding
      :param wrap: wrap children values with this
      :param size: size of window
      :param step: step size
      :return: transformation