How to use the stestr.results.wasSuccessful function in stestr

elapsed_time = stop_time - start_time

    if count_tests('status', '.*') == 0:
        print("The test run didn't actually run any tests", file=sys.stderr)
        return 1
    if post_fails:
        print_fails(stdout)
    if not no_summary:
        print_summary(stdout, elapsed_time)

    # NOTE(mtreinish): Ideally this should live in testtools streamSummary
    # this is just in place until the behavior lands there (if it ever does)
    if count_tests('status', '^success$') == 0:
        print("\nNo tests were successful during the run", file=sys.stderr)
        return 1
    return 0 if results.wasSuccessful(summary) else 1