code: def forward(self, prev_nodes):
      assert len(self.ops) == len(prev_nodes)
      out = [op(node) for op, node in zip(self.ops, prev_nodes)]
      out = [self.drop_path(o) if o is not None else None for o in out]
      return self.input_switch(out)
  
imports: import torch
  import torch.nn
  import torch.nn.functional
  import ops
  import numpy
  from nni.nas.pytorch import mutables
  from utils import parse_results
  from aux_head import DistillHeadCIFAR, DistillHeadImagenet, AuxiliaryHeadCIFAR, AuxiliaryHeadImageNet
label_desc: Use image node_id 2 for calling the Node obj's underlying member method code with example usage: obj.forward(prev_nodes) and returns: self