Entity/Job.php
public function removeSchedule(ScheduleInterface $schedule)
    {
        if($schedule instanceof Schedule)
        {
            $schedule->setJob(null);
        }

        parent::removeSchedule($schedule);
    }
public function removeSchedule(ScheduleInterface $schedule)
    {
        if($schedule instanceof Schedule)
        {
            $schedule->setJob(null);
        }

        parent::removeSchedule($schedule);
    }
{@inheritdoc}