> curl --data @- -X PUT '-H if-match: "30050093"' --dump - http://_api/localhost:8529/document/73482/30050094
{ "World" : "Hello" }

HTTP/1.1 412 Precondition Failed
content-type: application/json; charset=utf-8

{
  "_rev": "30050094",
  "_id": "73482/30050094",
  "error": true
}