* Registers a task with a task handler.
*
* @param $taskName A task name to register the task on
- * @param $taskInstance The instance we should register as a task
+ * @param $taskInstance An instance of a Taskable class
* @return void
*/
- function registerTask ($taskName, Visitable $taskInstance);
+ function registerTask (string $taskName, Taskable $taskInstance);
/**
* Checks whether tasks are left including idle task