static ErrorCode fromBusError(Error mbusError) {
        return mbusError.isFatal() && !MBUS_FATALS_HANDLED_AS_TRANSIENT.contains(mbusError.getCode())
                ? ERROR : TRANSIENT_ERROR;
    }
Return types for the server.

@author Einar M R Rosenvinge
@author Steinar Knutsen
vespaclient-container-plugin/src/main/java/com/yahoo/vespa/http/server/ErrorCode.java