svoid removeNonStreaksFromBitSetShorterThan(BitSet bs, int min) {
  if (bs == null) ret;
  int n = bs.length();
  int i = 0;
  while (i < n) {
    int j = bs.nextSetBit(i);
    if (j-i < min)
      set(i, j, true);
    i = j;
  }
}