Invariant (documentation 1.6.1 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
@API(status=MAINTAINED,
     since="1.0")
public interface Invariant<T>
```

- Method Summary
  
  All Methods Instance Methods Abstract Methods
  Modifier and Type Method Description
  
  void check(T model)

- Method Detail
  - check
```
void check(T model)
```