function roleCount($UserID = null)
	{
		if ($UserID === null)
		    throw new \RbacUserNotProvidedException ("\$UserID is a required argument.");

		$Res = Jf::sql ( "SELECT COUNT(*) AS Result FROM {$this->tablePrefix()}userroles WHERE UserID=?", $UserID );
		return (int)$Res [0] ['Result'];
	}