@Parameters
  public static Collection<Object[]> getParameters() {
    List<Object[]> versionsToTest = new ArrayList<>();
    for (int v = HFile.MIN_FORMAT_VERSION; v <= HFile.MAX_FORMAT_VERSION; ++v)
      versionsToTest.add(new Integer[] { v });
    return versionsToTest;
  }
The number of used fields by version. Indexed by version minus two. Min version that we support
is V2
hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/TestFixedFileTrailer.java