WordPress/wp-includes/blocks/text-columns/block.json

{
	"name": "core/text-columns",
	"icon": "columns",
	"category": "design",
	"attributes": {
		"content": {
			"type": "array",
			"source": "query",
			"selector": "p",
			"query": {
				"children": {
					"type": "string",
					"source": "html"
				}
			},
			"default": [
				{},
				{}
			]
		},
		"columns": {
			"type": "number",
			"default": 2
		},
		"width": {
			"type": "string"
		}
	},
	"supports": {
		"inserter": false
	}
}