Transition 2.2.2 API

```
public interface Transition

                    
```
A class to animate between a Target's current drawable and the result of an image request.
NOTE: A Target must implement TransitionTarget to support applying Transitions. If the Target does not implement TransitionTarget, any Transitions will be ignored.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`public interface`	`Transition.Factory`

Method Summary

Modifier and Type	Method	Description
`abstract Unit`	`transition()`	Start the transition animation.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - transition
```
@MainThread() abstract Unit transition()
```
    Start the transition animation.
    Implementations are responsible for calling the correct Target lifecycle callback. See CrossfadeTransition for an example.