public function getFormId()
    {
        // allowed are a-zA-Z0-9-_:.
        // no spaces

        $form = $this->getForm();
        $formId = $form->getName();

        if ($form instanceof FormCollectionInterface) {
            $formId .= '_' . $this->getEntityContainer()->getName();
        }

        $formId .= '_' . $this->getName();
        return $formId;
    }