Customer/EventListener/CustomerListener.php
protected function scheduleParentChangeEvents(CustomerInterface $customer)
    {
        if (!$customer->hasChildren()) {
            return;
        }

        foreach ($customer->getChildren() as $child) {
            $this->persistenceHelper->scheduleEvent(CustomerEvents::PARENT_CHANGE, $child);
        }
    }
protected function scheduleParentChangeEvents(CustomerInterface $customer)
    {
        if (!$customer->hasChildren()) {
            return;
        }

        foreach ($customer->getChildren() as $child) {
            $this->persistenceHelper->scheduleEvent(CustomerEvents::PARENT_CHANGE, $child);
        }
    }
Schedules the parent change events.

@param CustomerInterface $customer