<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_authversion(job_args):
 """Get or infer the auth version. Based on the information found in the *AUTH_VERSION_MAP* the authentication version will be set to a correct value as determined by the **os_auth_version** parameter as found in the `job_args`. :param job_args: ``dict`` :returns: ``str`` """


    _version = job_args.get('os_auth_version')
    for version, variants in AUTH_VERSION_MAP.items():
        if _version in variants:
            authversion = job_args['os_auth_version'] = version
            return authversion
    else:
        raise exceptions.AuthenticationProblem(
            "Auth Version must be one of %s.",
            list(AUTH_VERSION_MAP.keys())
        )