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