@Documented
 @TypeQualifierNickname
 @Nonnegative(when=MAYBE)
 @Retention(value=RUNTIME)
public @interface CheckForSigned
Used to annotate a value that may be either negative or nonnegative, and
 indicates that uses of it should check for
 negative values before using it in a way that requires the value to be
 nonnegative, and check for it being nonnegative before using it in a way that
 requires it to be negative.