public Optional<Metric.Level> getPreviousStatus() {
    return Optional.ofNullable(previousStatus);
  }
@Test
  public void getPreviousStatus_returns_empty_when_previousStatus_is_null() {
    QGChangeEvent underTest = new QGChangeEvent(project, branch, analysis, configuration, previousStatus, supplier);

    assertThat(underTest.getPreviousStatus()).contains(previousStatus);
  }