public RiakResult(
	bool isSuccess = true,
	string errorMessage = null,
	ResultCode resultCode = ResultCode.Success
)

new : 
        ?isSuccess : bool * 
        ?errorMessage : string * 
        ?resultCode : ResultCode 
(* Defaults:
        let _isSuccess = defaultArg isSuccess true
        let _errorMessage = defaultArg errorMessage null
        let _resultCode = defaultArg resultCode ResultCode.Success
*)
-> RiakResult