public static ImmutableSet<HttpUrl> allSubPaths(String url) {
    return allSubPaths(HttpUrl.parse(url));
  }
@Test
  public void allSubPaths_whenNoSubPathWithTrailingSlash_returnsSingleUrl() {
    assertThat(allSubPaths("http://localhost/"))
        .containsExactly(HttpUrl.parse("http://localhost/"));
  }