{
	"@context": "https://www.w3.org/ns/activitystreams",
	"summary": "Sally retracted her offer to John",
	"type": "Undo",
	"actor": "http://sally.example.org",
	"object": {
		"type": "Offer",
		"actor": "http://sally.example.org",
		"object": "http://example.org/posts/1",
		"target": "http://john.example.org"
	}
}