Callable (Lucene 8.1.0 API)

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
```
@FunctionalInterface
public interface Callable
```
Functional interface which provides sole method call()

- Method Summary
  
  All Methods Instance Methods Abstract Methods
  Modifier and Type Method Description
  
  void call()

- Method Detail
  - call
```
void call()
```