src/Contao/Callback/ContainerHeaderCallbackListener.php
public function update($event, $value)
    {
        if (null === $value) {
            return;
        }

        $event->setAdditional($value);
        $event->stopPropagation();
    }
public function update($event, $value)
    {
        if (null === $value) {
            return;
        }

        $event->setAdditional($value);
        $event->stopPropagation();
    }
public function update ( $ event , $ value ) { if ( null === $ value ) { return ; } $ event -> setAdditional ( $ value ) ; $ event -> stopPropagation ( ) ; }
Update the event with the information returned by the callback.

@param GetParentHeaderEvent $event The event being emitted.
@param array                $value The additional information.

@return void
Update the event with the information returned by the callback .