private void fill_array(RandomNumberGenerator generator) 
  {
    boolean[] is_empty = new boolean[this.max_size];
    for (int i = 0; i < is_empty.length; i++) 
	{
      is_empty[i] = true;
    }
    int index;
    while (this.numbers_filled < this.max_size
        && this.numbers_generated < 1000000) 
	{
      index = generator.next_int(this.max_size);
      if (is_empty[index]) 
	  {
        is_empty[index] = false;
        this.numbers_filled++;
      }
      this.numbers_generated++;
    }
  }