private function createCreateForm(MessageType $entity)
    {
        $form = $this->createForm(MessageTypeType::class, $entity, array(
            'action' => $this->generateUrl('messagetype_create'),
            'method' => 'POST',
        ));
        $this->_addFunctionsToForm($form);

        $form->add('create_group', CheckboxType::class, array('label' => "This is a new group.", 'mapped' => false, 'required' => false));
        $form->add('submit', SubmitType::class, array('label' => 'Create'));

        return $form;
    }