@Test
void checkNonExistentUrl() {

    server.when(HttpRequest.request())
        .respond(HttpResponse.notFoundResponse());
    final MavenMetadataParser parser = new MavenMetadataParser(serverUrl, "com.github.robozonky",
            "robozonky-nonexistent");
    final Either<Throwable, Response> result = parser.apply(UUID.randomUUID()
        .toString());
    assertThat(result.getLeft()).isInstanceOf(FileNotFoundException.class);
}