It's my pleasure! For example in here

public Helper getHelper() {
    return new Helper(
            "group show\n" +
                    "group add <gid>\n" +
                    "group remove <gid>",
            "group add group1",
            "Add, Remove, Show groups that can be recognized by the bot"
    );
}

I think the strings (each continuation line) should be indented by the same amount, but I could be wrong since I don't use Java much. There are also some things with too much vertical whitespace and missing horizontal whitespace (e.g. between if and the opening bracket). Maybe SonarLint could help with stuff like that (never used it personally).