The source tarball contains a prebuilt Java class file. These are often included by mistake when developers generate a tarball without cleaning the source directory first. If there is no sign this was intended, consider reporting it as an upstream bug as it may be a DFSG violation.
The tag is present in Lintian version
That is the most recent version we know about.
We use semantic versions.
The patch number is a commit step indicator relative to the
release tag in our Git
You can find the detection logic for this version at commit ce6249d. For merge requests, please use the latest version in the Lintian check languages/java.