code: def main(argv=None):
      """Runs all unit tests."""
      _test_util.InstallStackTraceHandler()
      return _googletest.main(argv)
  
file_path: tensorflow-upstream/tensorflow/python/platform/test.py
imports: import functools
  from unittest import mock
  from tensorflow.python.framework import test_util
  from tensorflow.python.platform import googletest
  from tensorflow.python.framework.test_util import assert_equal_graph_def
  from tensorflow.python.framework.test_util import create_local_cluster
  from tensorflow.python.framework.test_util import TensorFlowTestCase
  from tensorflow.python.framework.test_util import gpu_device_name
  from tensorflow.python.framework.test_util import is_gpu_available
  from tensorflow.python.ops.gradient_checker import compute_gradient_error
  from tensorflow.python.ops.gradient_checker import compute_gradient
  from tensorflow.python.util.tf_export import tf_export
label_desc: Use image node_id 1 for calling a global function with example usage: main(argv) and returns: _googletest