Extensions

All Known Subinterfaces:

ExtensionsImpl

All Known Implementing Classes:

ActorSystem
```
public interface Extensions
```
API for registering and looking up extensions.
Not for user extension.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`<T extends Extension> T`	`extension(ExtensionId<T> ext)`	Returns the payload that is associated with the provided extension throws an IllegalStateException if it is not registered.
`boolean`	`hasExtension(ExtensionId<? extends Extension> ext)`	Returns whether the specified extension is already registered, this method can potentially block, waiting for the initialization of the payload, if is in the process of registration from another Thread of execution
`<T extends Extension> T`	`registerExtension(ExtensionId<T> ext)`	Registers the provided extension and creates its payload, if this extension isn't already registered This method has putIfAbsent-semantics, this method can potentially block, waiting for the initialization of the payload, if is in the process of registration from another Thread of execution

- Method Detail
  - extension
```
<T extends Extension> T extension(ExtensionId<T> ext)
```
    Returns the payload that is associated with the provided extension throws an IllegalStateException if it is not registered. This method can potentially block, waiting for the initialization of the payload, if is in the process of registration from another Thread of execution
  - hasExtension
```
boolean hasExtension(ExtensionId<? extends Extension> ext)
```
    Returns whether the specified extension is already registered, this method can potentially block, waiting for the initialization of the payload, if is in the process of registration from another Thread of execution
  - registerExtension
```
<T extends Extension> T registerExtension(ExtensionId<T> ext)
```
    Registers the provided extension and creates its payload, if this extension isn't already registered This method has putIfAbsent-semantics, this method can potentially block, waiting for the initialization of the payload, if is in the process of registration from another Thread of execution