Initializes the animator object with a custom timing curve object.
- iOS 10.0+
- tvOS 10.0+
The duration of the animation, in seconds.
The object providing the timing information. This object must adopt the
An initialized animator object or
nil if the object could not be created.
Use this method to initialize the animator with a custom timing curve. After initializing the animator, you must add one or more animation blocks before calling starting the animations.