def METHOD_NAME(*test_subdirs):
    """
    Returns a list of tests in the common directory and any subdirectories
    given as additional arguments.
    """
    all_tests = []
    for test_dir in ('', *test_subdirs):
        tests = []
        test_dir_full = os.path.join(resource_root, 'test', 'tests', test_dir)
        for test in os.listdir(test_dir_full):
            if not os.path.isdir(os.path.join(test_dir_full, test)):
                tests.append(os.path.join('tests', test_dir, test))
        where = f'subdirectory {test_dir!r}' if len(test_dir) else 'directory'
        assert len(tests), f'No tests were found in the test {where}!'
        all_tests += sorted(tests)
    return all_tests