public function priorityLabel($todo)
    {
        switch (true) {
            case $todo->priority > 1:
                $label = 'highest';
                break;
            case $todo->priority == 1:
                $label = 'high';
                break;
            case $todo->priority == -1:
                $label = 'low';
                break;
            case $todo->priority < -1:
                $label = 'lowest';
                break;
            default:
                $label = 'normal';
                break;
        }

        return $label;
    }