private static Slime asSlimeMessage(String errorType, String message) {
        Slime slime = new Slime();
        Cursor root = slime.setObject();
        root.setString("error-code", errorType);
        root.setString("message", message);
        return slime;
    }
A HTTP JSON response containing an error code and a message

@author bratseth
container-core/src/main/java/com/yahoo/restapi/ErrorResponse.java