'Driver for Allowed field (protocol/ports list). Calls helpers as needed.
return: (bool, [list of AuditIssues])'

def inspect_allowed(self, item):

    errors = []
    err = self._port_range_exists(item.config.get('Allowed'))
    (errors.extend(err) if err else None)
    if errors:
        return (False, errors)
    return (True, None)
