fun <T> Viewer.beanItemContainer(type: Class<T>, init: BeanItemContainer<T>.() -> Unit = {}): BeanItemContainer<T>fun <T> Viewer.beanItemContainer(type: Class<T>, collection: Collection<T>, init: BeanItemContainer<T>.() -> Unit = {}): <ERROR CLASS>fun <T> Viewer.beanItemContainer(type: Class<T>, vararg bean: T, init: BeanItemContainer<T>.() -> Unit = {}): <ERROR CLASS>