ExtensionRegistrar (JUnit 5.5.0 API)

All Known Implementing Classes:

MutableExtensionRegistry
```
@API(status=INTERNAL,
     since="5.5")
public interface ExtensionRegistrar
```
An ExtensionRegistrar is used to register extension.

Since:

5.5

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`registerExtension(Extension extension, Object source)`	Register the supplied `Extension`, without checking if an extension of that type already exists.

- Method Detail
  - registerExtension
```
void registerExtension(Extension extension,
                       Object source)
```
    Register the supplied Extension, without checking if an extension of that type already exists.
    Semantics for Source
    
    If an extension is registered declaratively via @ExtendWith, the source and the extension should be the same object. However, if an extension is registered programmatically via @RegisterExtension, the source object should be the Field that is annotated with @RegisterExtension. Similarly, if an extension is registered programmatically as a lambda expression or method reference, the source object should be the underlying Method that implements the extension API.
    
    Parameters:
    
    extension - the extension to register; never null
    
    source - the source of the extension; never null