Return the items which get set since the setters also function as factories.
[Tickets] Added source constants on the Model.
Added Model::exists()
Made Client::$endpointClasses public (for now anyways)
Validate Endpoint instances used in Models throughout the whole inheritance tree.
Ante up the requirements.
Make it easier to batch populate a Collection with result sets straight from the API.
CS (visibility order)
Started work on basic CRUD operations on Models.
Keep the endpoint's URL available via each Model.
Refactoring the Tickets Endpoint.