KeyExtractor (TomEE :: Container :: Java EE 9.0.0 API)

```
public interface KeyExtractor<K,V>
```
Extracts an immutable key for this object. It is important for the key to not be mutable and that the key value itself is not changed in the object. If this happens any AutoIndex, or Map using this key will break.

- Method Summary
  
  All Methods Instance Methods Abstract Methods
  Modifier and Type Method Description
  
  K getKey(V value)
  Gets the immutable key for the specified value.

- Method Detail
  - getKey
```
K getKey(V value)
```
    Gets the immutable key for the specified value.
    
    Returns:
    
    gets the immutable key for the specified value