public void trimTrailingZeros() {
    int idx = wlen - 1;
    while (idx >= 0 && bits[idx / PAGE_SIZE][idx % PAGE_SIZE] == 0) {
      idx--;
    }
    wlen = idx + 1;
  }
Lowers numWords, the number of words in use,
by checking for trailing zero words.
ambry-utils/src/main/java/com/github/ambry/utils/OpenBitSet.java