container_layout.json

{
  "type": "container",
  "child_blocks": [
    {
      "type": "layout",
      "label": "Layout",
      "rows": [
        {
          "items": [
            {
              "block": {
                "type": "divider",
                "block_id": "child"
              }
            }
          ]
        }
      ],
      "block_id": "layout"
    }
  ],
  "width": "standard",
  "is_collapsible": false,
  "default_collapsed": false,
  "has_header_divider": false,
  "block_id": "container",
  "title": {
    "type": "plain_text",
    "text": "Container"
  }
}