code: def _prepare_reference(self):
      def init_refs(m):
          name = m.__class__.__name__
          if name.find("ReLU") != -1:
              m.ref_inp_list = []
              m.ref_out_list = []
  
      def ref_forward(self, x):
          self.ref_inp_list.append(x.data.clone())
          out = F.relu(x)
          self.ref_out_list.append(out.data.clone())
          return out
  
      def ref_replace(m):
          name = m.__class__.__name__
          if name.find("ReLU") != -1:
              m.forward = types.MethodType(ref_forward, m)
  
      self.model.apply(init_refs)
      self.model.apply(ref_replace)
  
file_path: tensorwatch/tensorwatch/saliency/deeplift.py
imports: from .backprop import GradxInputExplainer
  import types
  import torch.nn.functional
  from torch.autograd import Variable
label_desc: Use image node_id 2 for calling the DeepLIFTRescaleExplainer obj's underlying member method code with example usage: obj._prepare_reference() and returns: out