code: def test_multi_device(self):
      devices = ("cuda:0", "cuda:1")
      for current_dev, tensor_dev in product(devices, devices):
          with torch.cuda.device(current_dev):
              self.gen_single_type_test(
                  param_type=torch.float, device=tensor_dev
              )
  
imports: from itertools import product
  import random
  import unittest
  import torch
  import apex
label_desc: Use image node_id 4 for calling the TestFusedSGD obj's underlying member method code with example usage: obj.test_multi_device() without return types