Github user kinow commented on the issue:
https://github.com/apache/commons-lang/pull/275
Back to WIP. Please avoid merging it for now. Gilles noted in the mailing
list that the Observable/Observer classes have been deprecated in Java 9. So we
will probably go with the deprecation/removal path instead.
Link to the discussion in the mailing list:
https://markmail.org/message/efy52lul5pzbznut---
