@Override
  public String toString() {
    int iMax = length() - 1;
    if (iMax == -1) {
      return "[]";
    }

    // Double.toString(Math.PI).length() == 17
    StringBuilder b = new StringBuilder((17 + 2) * (iMax + 1));
    b.append('[');
    for (int i = 0; ; i++) {
      b.append(longBitsToDouble(longs.get(i)));
      if (i == iMax) {
        return b.append(']').toString();
      }