docs: public void removeMask(long[] mask) {
      int dest = BitsUtil.nextSetBit(mask, 0);
      if(dest < 0) {
        return;
      }
      int src = BitsUtil.nextSetBit(mask, dest);
      while(src < numEntries) {
        if(!BitsUtil.get(mask, src)) {
          entries[dest] = entries[src];
          dest++;
        }
        src++;
      }
      int rm = src - dest;
      while(dest < numEntries) {
        entries[dest] = null;
        dest++;
      }
      numEntries -= rm;
    }