WordPress/wp-includes/blocks/spacer/block.json

{
	"$schema": "https://schemas.wp.org/trunk/block.json",
	"apiVersion": 2,
	"name": "core/spacer",
	"title": "Spacer",
	"category": "design",
	"description": "Add white space between blocks and customize its height.",
	"textdomain": "default",
	"attributes": {
		"height": {
			"type": "string",
			"default": "100px"
		},
		"width": {
			"type": "string"
		}
	},
	"usesContext": [ "orientation" ],
	"supports": {
		"anchor": true
	},
	"editorStyle": "wp-block-spacer-editor",
	"style": "wp-block-spacer"
}