def METHOD_NAME(cert_file, saltenv="base"):
    """
    Get the serial number of a certificate file
    cert_file (str):
        The certificate file to find the serial for. Can be a local file or a
        a file on the file server (``salt://``)
    Returns:
        str: The serial number of the certificate if found, otherwise None
    CLI Example:
    .. code-block:: bash
        salt '*' certutil.get_cert_serial <certificate name>
    """
    cert_file = __salt__["cp.cache_file"](cert_file, saltenv)
    # Since we're allowing a path, let's make sure it exists
    if not os.path.exists(cert_file):
        msg = "cert_file not found: {}".format(cert_file)
        raise CommandExecutionError(msg)
    cmd = 'certutil.exe -silent -verify "{}"'.format(cert_file)
    out = __salt__["cmd.run"](cmd)
    # match serial number by paragraph to work with multiple languages
    matches = re.search(r":\s*(\w*)\r\n\r\n", out)
    if matches is not None:
        return matches.groups()[0].strip()
    else:
        return None