@Override
 public void onInit(List<? extends IndexCommit> commits) throws IOException {
   verifyCommitOrder(commits);
   numOnInit++;
   // On init, delete all commit points:
   for (final IndexCommit commit : commits) {
     commit.delete();
     assertTrue(commit.isDeleted());
   }
 }
 @Override
 public boolean isDeleted() {
   return cp.isDeleted();
 }