'Specify an authentication method for the server.'

def opt_auth(self, description):

    try:
        self.addChecker(makeChecker(description))
    except UnsupportedInterfaces as e:
        raise usage.UsageError(('Auth    plugin    not    supported:    %s' % e.args[0]))
    except InvalidAuthType as e:
        raise usage.UsageError(('Auth    plugin    not    recognized:    %s' % e.args[0]))
    except Exception as e:
        raise usage.UsageError(('Unexpected    error:    %s' % e))
