|  | package javax.annotation.meta; | 
|  |  | 
|  | /** | 
|  | * Used to describe the relationship between a qualifier T and the set of values | 
|  | * S possible on an annotated element. | 
|  | * | 
|  | * In particular, an issues should be reported if an ALWAYS or MAYBE value is | 
|  | * used where a NEVER value is required, or if a NEVER or MAYBE value is used | 
|  | * where an ALWAYS value is required. | 
|  | * | 
|  | * | 
|  | */ | 
|  | public enum When { | 
|  | /** S is a subset of T */ | 
|  | ALWAYS, | 
|  | /** nothing definitive is known about the relation between S and T */ | 
|  | UNKNOWN, | 
|  | /** S intersection T is non empty and S - T is nonempty */ | 
|  | MAYBE, | 
|  | /** S intersection T is empty */ | 
|  | NEVER; | 
|  |  | 
|  | } |