Nested element in custom renderer

Hello,

i want to create nested element container

'error' => [
    'container' => 'div class="ui error message visible"',
    'item' => 'li',
]

but i dont know, how can i make layout for that container, to render like this

<div class=...>
	<ul class>
	</ul>
</div>

this should be parent element for that error items.

any ideas?

Thanks for help
Lubos