/**
* Checks if another Activity matches the general information of another.
*/
- public function isSimilarTo(Activity $activityB): bool
+ public function isSimilarTo(self $activityB): bool
{
return [$this->type, $this->entity_type, $this->entity_id] === [$activityB->type, $activityB->entity_type, $activityB->entity_id];
}