To run the tool and see its output, use the command java -jar FinerDupes_v2.jar from your terminal, provided you have a Java Runtime Environment (JRE) installed.

Use an IDE like IntelliJ IDEA to decompile the classes and see what the code is actually doing.

Knowing the source (e.g., a specific GitHub repo or a Minecraft modding forum) would allow for a more detailed functional report.