Github user Ethanlm commented on the issue:
https://github.com/apache/storm/pull/2546
The dependency rocksdbjni.jar is present in lib/ directory after packaging
so there shouldn't be exceptions during nimbus daemon startup. But changing
from `isImplementationOfClass` to `isString ` makes sense to me. It's just like
what we do for `SUPERVISOR_BLOBSTORE` and `NIMBUS_BLOBSTORE`---
