java.lang.Object
- akka.actor.setup.Setup
- - akka.actor.typed.ExtensionSetup<T>
  - - akka.actor.typed.AbstractExtensionSetup<T>

```
public abstract class AbstractExtensionSetup<T extends Extension>
extends ExtensionSetup<T>
```
Scala 2.11 API: Each extension typically provide a concrete ExtensionSetup that can be used in ActorSystemSetup when starting the ActorSystem to replace the default implementation of the extension. Intended for tests that need to replace extension with stub/mock implementations.

public AbstractExtensionSetup(ExtensionId<T> extId,
                              scala.Function1<ActorSystem<?>,T> createExtension)

Class AbstractExtensionSetup<T extends Extension>