@Override
  public Health check() {
    if (isConnectedToDB()) {
      return Health.GREEN;
    }
    return RED_HEALTH;
  }
@Test
  public void status_is_RED_with_single_cause_if_any_error_occurs_when_checking_DB() {
    when(isAliveMapper.isAlive()).thenThrow(new RuntimeException("simulated runtime exception when querying DB"));

    Health health = underTest.check();

    verifyRedStatus(health);
  }