In spray for scala, get a FromRequestUnmarshaller from an ordinary Unmarshaller -
    in scala spray, there way convert unmarshaller[t]  fromrequestunmarshaller[t] . i'm stuck trying make entity  directive work without using implicits. example:   ... } ~ post {   path("mypath") {     entity(sprayjsonunmarshaller[mycaseclass](mycaseclassrootjsonformat)) { mycaseclass =>       complete { handle(mycaseclass) }     }   } ~ ...   compiler error:   multiple markers @ line     - type mismatch; found : spray.httpx.unmarshalling.unmarshaller[mycaseclass] (which       expands to) spray.httpx.unmarshalling.deserializer[spray.http.httpentity,mycaseclass]       required: spray.httpx.unmarshalling.fromrequestunmarshaller[?] (which expands to)       spray.httpx.unmarshalling.deserializer[spray.http.httprequest,?]     - type mismatch; found : spray.httpx.unmarshalling.unmarshaller[mycaseclass] (which       expands to) spray.httpx.unmarshalling.deserializer[spray.http.httpentity,mycaseclass]       required: spray.httpx.unmarshalling.fromrequestunmarshaller[?] (which...