public LongValue increment(long increment) {
    this.value += increment;
    this.set = true;
    return this;
  }
@Test
  public void multiples_calls_to_increment_long_increment_the_value() {
    LongValue variationValue = new LongValue()
      .increment(10L)
      .increment(95L);

    verifySetVariationValue(variationValue, 105L);
  }