@Test
 public void check_WhenSimbaIsNotAlive_ReturnsUnhealthy() throws Exception {
   when(simbaGatewayMock.isSimbaAlive()).thenReturn(false);
   Result actual = simbaHealthCheck.check();
   assertThat(actual).isEqualTo(Result.unhealthy("Could not establish connection"));
 }
 @Test
 public void check_WhenSimbaIsAlive_ReturnsHealthy() throws Exception {
   when(simbaGatewayMock.isSimbaAlive()).thenReturn(true);
   Result actual = simbaHealthCheck.check();
   assertThat(actual).isEqualTo(Result.healthy());
 }