A set of methods used by the delegate to respond, with a preview view controller and a commit view controller, to the user pressing a view object on the screen of a device that supports 3D Touch.
To learn about 3D Touch, read Adopting 3D Touch on iPhone.
Providing Preview and Commit Views for 3D Touch
Implementing Peek and Pop
Accelerate actions in your app by providing shortcuts to preview content in detail view controllers.