Hello Min Sun, is there a particular reason why you opt for / stick to distribution `UNRELEASED` for a package already monitored by the tracker?[1] It is the entry e.g., `dch -i` puts into file `/debian/changelog` when you start to work on a new version (increment) of a package. After all other other work on your side is done, an eventual change to the string `unstable` (then lower case only) is one of the keys necessary to let results of your work enter branch `unstable`, and later `testing`, etc.
Regards, Norwid [1] https://tracker.debian.org/pkg/libcommons-validator-java