@Override
  public void start() {
    DatabaseVersion.Status status = version.getStatus();
    checkState(status == UP_TO_DATE || status == FRESH_INSTALL, "Compute Engine can't start unless Database is up to date");
  }
@Test
  public void start_has_no_effect_if_status_is_UP_TO_DATE() {
    when(databaseVersion.getStatus()).thenReturn(UP_TO_DATE);

    underTest.start();

    verify(databaseVersion).getStatus();
    verifyNoMoreInteractions(databaseVersion);
  }