code: def testSubcommand_ExitCode(self):
      tb = program.TensorBoard(
          plugins=[core_plugin.CorePluginLoader],
          assets_zip_provider=fake_asset_provider,
          subcommands=[_TestSubcommand()],
      )
      _TestSubcommand.run.return_value = 77
      tb.configure(("tb", "test"))
      self.assertEqual(tb.main(), 77)
  
imports: import argparse
  import io
  import sys
  from unittest import mock
  from tensorboard import program
  from tensorboard import test
  from tensorboard.plugins import base_plugin
  from tensorboard.plugins.core import core_plugin
label_desc: Use image node_id 6 for calling the SubcommandTest obj's underlying member method code with example usage: obj.testSubcommand_ExitCode() without return types