Package pro.fessional.wings.slardar.concur

the default key of @DoubleKill is array of [method, uid, args].
 - if the args is not easy to equals, use expression() to pickup
 - if uid is useless, use principal() to ignore
 - if expression() is no problem, toggle checkNull() to skip

Note: When executing async and using with AOP annotations such as @Cacheable,
make sure that DK is executed first. Otherwise, the result of the async execution
cannot be processed correctly. If you can not guarantee the first execution,
do not use at the same time.

Repeated interception within the JVM will throw a no-stack exception to stop the execution,
the caller needs to `catch` their own.
- DoubleKillException will `throw` except those in sync execution.