@Test public void checkInternetConnectivityShouldNotThrowAnExceptionWhenStrategyIsNotNull() {

  // given
  final InternetObservingStrategy strategy = new SocketInternetObservingStrategy();
  final ErrorHandler errorHandler = new DefaultErrorHandler();
  // when
  final Single<Boolean> single =
      ReactiveNetwork.checkInternetConnectivity(strategy, TEST_VALID_HOST, TEST_VALID_PORT,
          TEST_VALID_TIMEOUT, TEST_VALID_HTTP_RESPONSE, errorHandler);
  // then
  assertThat(single).isNotNull();
}