code: def forward(self, x):
      return self.pointwise(self.depthwise(x))
  
imports: import os
  import random
  from pathlib import Path
  import nni
  import torch
  import torch.nn.functional
  import nni.retiarii.nn.pytorch
  import nni.retiarii.strategy
  from nni.retiarii import model_wrapper
  from nni.retiarii.evaluator import FunctionalEvaluator
  from nni.retiarii.experiment.pytorch import RetiariiExeConfig, RetiariiExperiment, debug_mutated_model
  from torch.utils.data import DataLoader
  from torchvision import transforms
  from torchvision.datasets import MNIST
label_desc: Use image node_id 2 for calling the DepthwiseSeparableConv obj's underlying member method code with example usage: obj.forward(x) and returns: self