{
  "objectType": "activity",
  "verb": "rsvp-yes",
  "url": "http://example.com/this/rsvp",
  "actor": {
    "objectType": "person",
    "displayName": "Alice",
    "url": "http://example.com/alice"
  },
  "object": {"url": "http://example.com/event"}
}
