Return type:
         pruned_tensor (torch.Tensor)
prune(t, default_mask=None, importance_scores=None)
  Computes and returns a pruned version of input tensor "t"
  according to the pruning rule specified in "compute_mask()".

  Parameters:
     * **t** (*torch.Tensor*) -- tensor to prune (of same
       dimensions as "default_mask").

     * **importance_scores** (*torch.Tensor*) -- tensor of
       importance scores (of same shape as "t") used to compute
       mask for pruning "t". The values in this tensor indicate
       the importance of the corresponding elements in the "t"
       that is being pruned. If unspecified or None, the tensor
       "t" will be used in its place.

     * **default_mask** (*torch.Tensor**, **optional*) -- mask
       from previous pruning iteration, if any. To be considered
       when determining what portion of the tensor that pruning
       should act on. If None, default to a mask of ones.
