svoid removeNonStreaksFromBitSetShorterThan(BitSet bs, int min) {
  if (bs == null) ret;
  int n = bs.length();
  int i = -1;
  while true {
    i = bs.nextClearBit(i+1);
    if (i >= n) break;
    int j = bs.nextSetBit(i+1);
    if (j-i < min)
      bs.set(i, j, true);
    i = j;
  }
}