All the setup/teardown/pre/post/conditions template methods now are required to return void. This was warned with phpunit 7 and now is enforced. At the same time, fix a few wrong function names, provider data and param types, return statements...
The tests needed to use the API in order to trigger the user_graded event that occurs when the course final grade has changed.
Unit test was introduced in MDL-40697 when the generator for quiz activity was setting grade=0
This event is triggered when teacher manually edits the grade in gradebook.