$builder->add('classcategory_id1', 'choice', array(
                        'label' => $Product->getClassName1(),
                        'choices'   => array('__unselected' => '選択してください') + $Product->getClassCategories1(),
                        'choice_attr' => function($val, $key, $index) {
                            return ['data-icon' => $this->config['front_urlpath'].'/img/icon_'.$val.'.jpg'];
                        },
                    ));