code: def explain(self, inp, ind=None, raw_inp=None):
      grad = self._backprop(inp, ind)
      return grad.abs()
  
imports: import numpy
  from torch.autograd import Variable, Function
  import torch
  import types
label_desc: Use image node_id 2 for calling the SaliencyExplainer obj's underlying member method code with example usage: obj.explain(inp, ind, raw_inp) and returns: grad