Right now groups are ordered by their first occurrence in the group_by callable. I've run into a use-case where I cannot guarantee the order of that first occurrence, and need to be able to sort the groups after they are defined. It would be nice if there was an additional option to define a comparator for sorting groups.

In my specific case, I have a group_by function that looks like this:

'group_by' => function ($entity) use ($soonThreshold) {
    switch (true) {
        case $entity->isComplete():
            return 'Complete';
        case $entity->willBeComplete():
            return 'Will Be Complete';
        case $entity->isOverDue():
            return 'Not Complete - Overdue';
        case $entity->isDueBy($soonThreshold):
            return 'Not Complete - Due Soon';
        default:
            return 'Not Complete - Due Later';
    }
}

My application requires these groups to be presented in this order, but I have no way to guarantee that the entities will be ordered in a way that produces that order (even with a query builder).