public void testInternalVersionConflict() throws Exception {
    assertFalse(
        VersionType.INTERNAL.isVersionConflictForWrites(10, Versions.MATCH_ANY, randomBoolean()));
    assertFalse(VersionType.INTERNAL.isVersionConflictForReads(10, Versions.MATCH_ANY));

    // if we didn't find a version (but the index does support it), we don't like it unless
    // MATCH_ANY
    assertTrue(
        VersionType.INTERNAL.isVersionConflictForWrites(Versions.NOT_FOUND, 10, randomBoolean()));
    assertTrue(VersionType.INTERNAL.isVersionConflictForReads(Versions.NOT_FOUND, 10));
    assertFalse(
        VersionType.INTERNAL.isVersionConflictForWrites(
            Versions.NOT_FOUND, Versions.MATCH_ANY, randomBoolean()));
    assertFalse(
        VersionType.INTERNAL.isVersionConflictForReads(Versions.NOT_FOUND, Versions.MATCH_ANY));

    // deletes
    assertFalse(
        VersionType.INTERNAL.isVersionConflictForWrites(
            Versions.NOT_FOUND, Versions.MATCH_DELETED, true));
    assertFalse(VersionType.INTERNAL.isVersionConflictForWrites(10, Versions.MATCH_DELETED, true));

    // and the stupid usual case
    assertFalse(VersionType.INTERNAL.isVersionConflictForWrites(10, 10, randomBoolean()));
    assertFalse(VersionType.INTERNAL.isVersionConflictForReads(10, 10));
    assertTrue(VersionType.INTERNAL.isVersionConflictForWrites(9, 10, randomBoolean()));
    assertTrue(VersionType.INTERNAL.isVersionConflictForReads(9, 10));
    assertTrue(VersionType.INTERNAL.isVersionConflictForWrites(10, 9, randomBoolean()));
    assertTrue(VersionType.INTERNAL.isVersionConflictForReads(10, 9));

    // Old indexing code, dictating behavior
    //        if (expectedVersion != Versions.MATCH_ANY && currentVersion != Versions.NOT_SET) {
    //            // an explicit version is provided, see if there is a conflict
    //            // if we did not find anything, and a version is provided, so we do expect to find
    // a doc under that version
    //            // this is important, since we don't allow to preset a version in order to handle
    // deletes
    //            if (currentVersion == Versions.NOT_FOUND) {
    //                throw new VersionConflictEngineException(shardId, index.type(), index.id(),
    // Versions.NOT_FOUND, expectedVersion);
    //            } else if (expectedVersion != currentVersion) {
    //                throw new VersionConflictEngineException(shardId, index.type(), index.id(),
    // currentVersion, expectedVersion);
    //            }
    //        }
    //        updatedVersion = (currentVersion == Versions.NOT_SET || currentVersion ==
    // Versions.NOT_FOUND) ? 1 : currentVersion + 1;
  }