function Sorted(superset) {
// Save a reference to the original collection
this._superset = superset;
this._reverse = false;
this._comparator = null;
// The idea is to keep an internal backbone collection with the paginated
// set, and expose limited functionality.
this._collection = new Backbone.Collection(superset.toArray());
proxyCollection(this._collection, this);
this.listenTo(this._superset, 'add', onAdd);
this.listenTo(this._superset, 'remove', onRemove);
this.listenTo(this._superset, 'change', onChange);
this.listenTo(this._superset, 'reset', sort);
}
function Filtered(superset) {
// Save a reference to the original collection
this._superset = superset;
// The idea is to keep an internal backbone collection with the filtered
// set, and expose limited functionality.
this._collection = new Backbone.Collection(superset.toArray());
proxyCollection(this._collection, this);
// Set up the filter data structures
this.resetFilters();
this.listenTo(this._superset, 'reset sort', execFilter);
this.listenTo(this._superset, 'add change', onAddChange);
this.listenTo(this._superset, 'remove', onModelRemove);
this.listenTo(this._superset, 'all', onAll);
}