public String toString() {
        String opCodeString, resultCodeString, questionTypeString, recordTypeString;

        opCodeString = switch (this.opCode) {
        case QUERY -> "QUERY";
        case WACK -> "WACK";
        default -> Integer.toString(this.opCode);
        };
        resultCodeString = switch (this.resultCode) {
        case FMT_ERR -> "FMT_ERR";
        case SRV_ERR -> "SRV_ERR";

        final String questionClassString;
        String recordTypeString;
        final String recordClassString;

        opCodeString = switch (opCode) {
        case QUERY -> "QUERY";
        case WACK -> "WACK";
        default -> Integer.toString(opCode);
        };
        resultCodeString = switch (resultCode) {
        case FMT_ERR -> "FMT_ERR";
        case SRV_ERR -> "SRV_ERR";
        case IMP_ERR -> "IMP_ERR";

        packet.opCode = NameServicePacket.WACK;
        packet.resultCode = NameServicePacket.SRV_ERR;
        packet.questionType = NameServicePacket.NBSTAT;
        packet.recordType = NameServicePacket.NBSTAT;
        expectedString =

        Field opCodeField = NameServicePacket.class.getDeclaredField("opCode");
        opCodeField.setAccessible(true);
        opCodeField.set(nameQueryResponse, 7); // WACK opCode, which is not QUERY (0)

        // Ensure 'resultCode' is 0 for this test to isolate opCode condition
        Field resultCodeField = NameServicePacket.class.getDeclaredField("resultCode");