code: def testSubcommand_MayRequirePositionals(self):
      def define_flags(parser):
          parser.add_argument("payload")
  
      tb = program.TensorBoard(
          plugins=[core_plugin.CorePluginLoader],
          assets_zip_provider=fake_asset_provider,
          subcommands=[_TestSubcommand(define_flags=define_flags)],
      )
      with self.assertRaises(SystemExit):
          tb.configure(("tb", "test"))
      self.assertIn("required", self.stderr.getvalue())
      self.assertIn("payload", self.stderr.getvalue())
      self.stderr.truncate(0)
  
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 8 for calling the SubcommandTest obj's underlying member method code with example usage: obj.testSubcommand_MayRequirePositionals() without return types