private List<IDeviceID> genBatchDevices() {
    Random random = new Random();
    List<IDeviceID> devices = new ArrayList<>();
    int fatherLength = random.nextInt(10) + 10;
    int deviceLength = random.nextInt(5) + 5;

    for (int i = 0; i < batchSize; i++) {
      StringBuilder curDevice = new StringBuilder(sg);
      for (int j = 0; j < fatherLength; j++) {
        curDevice.append(chars.charAt(random.nextInt(chars.length())));
      }
      curDevice.append('.');
      for (int k = 0; k < deviceLength; k++) {
        curDevice.append(chars.charAt(random.nextInt(chars.length())));
      }
      devices.add(Factory.DEFAULT_FACTORY.create(curDevice.toString()));
    }
    return devices;
  }
This is a not active test class, which can be used for general index testing when there is a new
DeviceGroup hash algorithm
iotdb-core/confignode/src/test/java/org/apache/iotdb/confignode/manager/hash/DeviceGroupHashExecutorManualTest.java