{ "@context": "https://www.w3.org/ns/activitystreams", "summary": "History of John's note", "type": "Collection", "items": [ { "summary": "Sally liked John's note", "type": "Like", "id": "http://activities.example.com/1", "actor": "http://sally.example.org", "published": "2015-11-12T12:34:56Z", "object": { "summary": "John's note", "type": "Note", "id": "http://notes.example.com/1", "attributedTo": "http://john.example.org", "content": "My note" } }, { "summary": "Sally no longer likes John's note", "type": "Undo", "id": "http://activities.example.com/2", "actor": "http://sally.example.org", "published": "2015-12-11T21:43:56Z", "object": "http://activities.example.com/1" } ] }