new_contents: import numpy as np
  import theano
  import theano.tensor as T
  import treeano.nodes as tn
  fX = theano.config.floatX
  
  # TODO change me
  # n = tn.SpatialRepeatNDNode
  n = tn.SpatialSparseUpsampleNode
  
  network = tn.SequentialNode(
      "s",
      [tn.InputNode("i", shape=(32, 32, 32, 32, 32)),
       n("us", upsample_factor=(2, 2, 2))]
  ).network()
  fn = network.function(["i"], ["s"])
  x = np.random.randn(32, 32, 32, 32, 32).astype(fX)
  
  """
  20150926 results:
  
  %timeit fn(x)
  
  SpatialRepeatNDNode: 663 ms
  SpatialSparseUpsampleNode: 424 ms
  """
  
subject: add upsample benchmark