The code contains now deprecated legacy log functions that will cause PHPUnit and Behat tests to fail, e.g.:

PHPUnit test:
mod_hsuforum_events_testcase::test_discussion_created_forumid_validation Unexpected debugging() call detected. Debugging: Invalid event functions defined in \mod_hsuforum\event\discussion_created

Behat test:
In Open Forums a user with access to multiple groups should be able to post a copy of a message to all the groups they have access to/Teacher is able to post a copy of a message to all groups in a separate group forum And I add a new discussion to "Separate group forum" Open Forum with:: debugging() message/s found: Invalid event functions defined in \mod_hsuforum\event\course_module_viewed

Since Moodle 4.2 the legacy log store is deprecated (see: https://tracker.moodle.org/browse/MDL-52805) and these functions therefore need to be removed.