@Test
public void if_the_environment_variable_is_set_the_guest_url_is_configured() {

    mockStatic(System.class);
    final String expectedConfig = "HOST:PORT";
    when(System.getenv(GUEST_URI_ENV_PROPERTY_KEY)).thenReturn(expectedConfig);
    assertThat(new GuestFeedSubscriber().determineGuestHostAndPort()).isEqualTo(expectedConfig);
}