NOTE: Blocking Differential Revisions must be also applied.
# perform installation of In-Portal (without modules and with some/all modules)
# confirm, that it's possible
# open In-Portal and do some common stuff, like browsing Front-End/Admin Console
# confirm, that no error happens
# create any class, e.g. new helper and don't register it in any unit config
# run `php tools/build_class_map.php` script
# confirm, that new class mention was added to a `/install/cache/class_map.php` file of module, where you've added the class
# try using the helper like `$this->Application->recallObject('HelperClassName');`
# confirm, that proper class instance was created