Helper to return known serializer based on
    pass output argument

def _get_serializer(output):
    '''
    Helper to return known serializer based on
    pass output argument
    '''
    serializers = salt.loader.serializers(__opts__)
    try:
        return getattr(serializers, output)
    except AttributeError:
        raise CommandExecutionError(
            "Unknown serializer '{0}' found for output option".format(output)
        )