Actually Eid exceptions do not extend their Java counterparts. It's good idea to rethink, is that the right way. Given for `ex instanceof EidIllegalStateException`, it's basically to chose what's more beneficial: ```java ex instanceof EidRuntimeException ``` or ```java ex instanceof IllegalStateException ``` We can't have both. There is also `EidContainer` interface, thus it can be like: ```java class EidIllegalStateException extends IllegalStateException implements EidContainer ```