code: def _test_multiple_gpu_mode(self, devices):
      if devices == "all":
          expected = torch.cuda.device_count()
      else:
          expected = len(devices)
      self.assertEqual(
          len([self.model.device] + self.model.other_device), expected
      )
  
file_path: poutyne/tests/framework/model/test_multi_gpu.py
imports: import os
  from unittest import skipIf
  import torch
  from torch import nn
  from poutyne import Model
  from tests.framework.model.base import ModelFittingTestCase
  from tests.framework.tools import SomeConstantMetric, repeat_batch_metric, repeat_batch_metric_value, some_batch_metric_1, some_batch_metric_2, some_constant_metric_value, some_data_tensor_generator, some_metric_1_value, some_metric_2_value
label_desc: Use image node_id 2 for calling the ModelTestMultiGPU obj's underlying member method code with example usage: obj._test_multiple_gpu_mode(devices) without return types