code: def rnn_unroll(cell, length, inputs=None, begin_state=None, input_prefix='', layout='NTC'):
      
      warnings.warn('rnn_unroll is deprecated. Please call cell.unroll directly.')
      return cell.unroll(length=length, inputs=inputs, begin_state=begin_state,
                         input_prefix=input_prefix, layout=layout)
docs: Deprecated. Please use cell.unroll instead