@Test(expected = IllegalArgumentException.class)
public void checkInternetConnectivityShouldThrowAnExceptionWhenStrategyIsNull() {

  // given
  final ErrorHandler errorHandler = new DefaultErrorHandler();
  // when
  ReactiveNetwork.checkInternetConnectivity(null, TEST_VALID_HOST, TEST_VALID_PORT,
      TEST_VALID_TIMEOUT, TEST_VALID_HTTP_RESPONSE, errorHandler);
  // then an exception is thrown
}