/**
 * Update the aggregate column in the related  object
 *
 * @param ConnectionInterface $con A connection object
 */
protected function updateRelated(ConnectionInterface $con)
{
    if ($ = $this->get()) {
        $->($con);
    }
    if ($this->old) {
        $this->old->($con);
        $this->old = null;
    }
}