uikit_admin-8.x-3.0/templates/block/block--system-messages-block.html.twig

{#
/**
 * @file
 * Theme override to display the system messages block.
 *
 * Removes wrapper elements from block so that empty block does not appear when
 * there are no messages.
 *
 * Available variables:
 * - content: The content of this block.
 * - attributes: array of HTML attributes populated by modules, intended to
 *   be added to the main container tag of this template.
 *   - id: A valid HTML ID and guaranteed unique.
 *
 * @see template_preprocess_block()
 * @see uikit_preprocess_block()
 *
 * @ingroup uikit_themeable
 */
#}
{% if content %}
  <div{{ attributes }}>
    {{ content }}
  </div>
{% endif %}