/**
   * get a random Integer number ∈ [minValue, maxValue)
   */
  public Integer getRandomNumberBetween(Integer minValue, Integer maxValue) {

    if (minValue > maxValue) {
      // swap position
      Integer tmp = minValue;
      minValue = maxValue;
      maxValue = tmp;
    }

    return Math.floor(Math.random() * (maxValue - minValue) + minValue);
  }