| Annotation Type | Description | 
|---|---|
| NonNull | 
 Indicates that a field, local variable, method return value or parameter can never be
  
null. | 
| NonNullByDefault | 
 Indicates that all fields, method return values or parameters can never be  
null in
 the annotated package or type. | 
| Nullable | 
 Indicates that a field, local variable, method return value or parameter can be
  
null. |