How to use the checklist.CopyrightHeadersValidator function in checklist

"""Go on a power trip by nitpicking the scikit-bio repo.

    Attempts to find things that are wrong with the repo -- these are usually
    annoying details introduced by human error. The code goes out of its way
    to nitpick as much as possible in order to maximize the effectiveness of
    the power trip.

    Returns
    -------
    int
        Return code: 0 if there were no validation errors, 1 otherwise. Useful
        as an exit code (e.g. for use with ``sys.exit``).

    """
    root = 'skbio'
    validators = [InitValidator(), CopyrightHeadersValidator(),
                  ExecPermissionValidator(), GeneratedCythonValidator(),
                  APIRegressionValidator()]

    return_code = 0
    for validator in validators:
        success, msg = validator.validate(root)

        if not success:
            return_code = 1
            sys.stderr.write('\n'.join(msg))
            sys.stderr.write('\n\n')

    return return_code