code: public void setDefaultFingerprints(int num) {
      setEnrolledFingerprints(
          IntStream.range(0, num)
              .mapToObj(
                  i ->
                      new Fingerprint(
                          /* name= */ "Fingerprint " + i,
                          /* groupId= */ 0,
                          /* fingerId= */ i,
                          /* deviceId= */ 0))
              .toArray(Fingerprint[]::new));
    }
docs: Enrolls the given number of fingerprints, which will be returned in {@link
  #getEnrolledFingerprints}.
  
  @param num the quantity of fingerprint item.