public function removePanel(PanelFacet $panel)
    {
        //some reordering have to happen here...
        $panels = $this->panelRepo->findPanelsAfter($panel);

        foreach ($panels as $afterPanel) {
            $afterPanel->setPosition($afterPanel->getPosition() - 1);
            $this->om->persist($afterPanel);
        }

        $this->om->remove($panel);
        $this->om->flush();
        //reorder the fields for the still standing panels
        $panels = $this->panelRepo->findAll();

        foreach ($panels as $panel) {
            $this->reorderFields($panel);
        }
    }