docs: int flipTriangles(long[] flippedB) {
      final int size = tris.size();
      int numflips = 0;
      BitsUtil.zeroI(flippedB);
      for(int i = 0; i < size; i++) {
        if(!BitsUtil.get(flippedB, i) && flipTriangle(i, flippedB) >= 0) {
          numflips += 2;
        }
      }
      if(LOG.isDebuggingFinest()) {
        LOG.debugFinest("Flips: " + numflips);
      }
      return numflips;
    }