code: def test_train_async(self):
      self._test_train(execution_mode=context.ASYNC)
  
imports: import gc
  import os
  import tempfile
  import time
  import tensorflow
  from tensorflow.python.client import device_lib
  from tensorflow.python.eager import context
  from tensorflow.python.eager import record
  from tensorflow.python.eager.benchmarks.resnet50 import resnet50
  from tensorflow.python.eager.benchmarks.resnet50 import resnet50_test_util
  from tensorflow.python.framework import test_util
label_desc: Use image node_id 13 for calling the ResNet50Test obj's underlying member method code with example usage: obj.test_train_async() without return types