How to filter a pivot table using Eloquent?

Laravel 4.1 brings native wherePivot and orWherePivot methods, which is directly a solution to my problem.

I try to setup all relationships in both directions as this allows for use of dynamic properties, eg $user->works().

class Collection extends Eloquent {
    public function contents()
    {
        return $this->belongsToMany('Content', 'collection_content', 'collection_id', 'content_id')->withPivot('collection_id', 'group_id', 'field_identifier');
    }
}

class Content extends Eloquent {
    public function collections()
    {
        return $this->belongsToMany('Collection', 'collection_content', 'collection_id', 'content_id')->withPivot('collection_id', 'group_id', 'field_identifier');
    }
}

class CollectionContent extends Eloquent {
    public function content()
    {
        return $this->belongsTo('Content');
    }

    public function collection()
    {
        return $this->belongsTo('Collection');
    }
}

Then query:

$works = User::find(1)->works()->where('active', 1)->get();

Eloquent's documentation is awful when it comes to the use of pivot tables. This is a great tutorial: http://www.developed.be/2013/08/30/laravel-4-pivot-table-example-attach-and-detach/