new_contents: """
  from "Striving for Simplicity - The All Convolutional Net"
  http://arxiv.org/abs/1412.6806
  
  """
  
  import treeano
  import treeano.sandbox.utils
  
  
  class _GuidedBackprop(treeano.sandbox.utils.OverwriteGrad):
  
      """
      based on Lasagne Recipes on Guided Backpropagation
      """
  
      def grad(self, inputs, out_grads):
          (inp,) = inputs
          (grd,) = out_grads
          dtype = inp.dtype
          return (grd * (inp > 0).astype(dtype) * (grd > 0).astype(dtype),)
  
  
  guided_backprop_relu = _GuidedBackprop(treeano.utils.rectify)
  
subject: add guided backprop relu