Decoder.of(“content/type”)(response => Validated.valid(_.content))
I think
```def createSession(client: Client): String = {
val d = SSession("spark", "spark1")
val headers = """{'Content-Type': 'application/json'}"""
val req = client.post("/sessions").withContent(d, "application/json")
Await.result {
req.send[Response]() map {
response => response.contentString
}
}
}```