```
@Retention(SOURCE)
@Target({METHOD,PARAMETER,FIELD})
public @interface Nullable
```
Denotes that a parameter, field or method return value can be null.
When decorating a method call parameter, this denotes that the parameter can legitimately be null and the method will gracefully deal with it. Typically used on optional parameters.
When decorating a method, this denotes the method might legitimately return null.
This is a marker annotation and it has no specific attributes.

Annotation Type Nullable