写了一个简单 Python 测试脚本，请问一下为什么运行显示测试用例为 0，我这里已经定义一个了吧

import unittest from viman import vimanApp class cli_tests(unittest.TestCase): argv_set = [ ['viman', '-h'], ['viman', '-V'], ['viman', '-Q'], ['viman', '-Sf', 'test.yml'], ['viman', '-S', 'https://github.com/vimscript/vim-snippets.git'], ['viman', '-Ur'], ['viman', '-R', 'https://github.com/vimscript/vim-snippets.git'], ['viman', '-Rn', 'a.vim'], ['viman', '-Rf', '~/.viman.yml'], ] def cli_testing(self): for argv in cli_tests.argv_set: self.assertEqual(vimanApp.main(argv), 0) if __name__ == '__main__': unittest.main()