//     [abc]de|[fgh] -> [fgh]de|[abc]. Now [fgh] is in the right place, but we need to swap [de]
    //     with [abc]: fgh[de]|a[bc] -> fgh[bc]|a[de]. Now we need to swap [a] with [bc]:
    //     fgh[b]c|[a]de -> fgh[a]c|[b]de. Finally we need to swap [c] with [b]:
    //     fgha[c]|[b]de -> fgha[b]|[c]de. Because these two blocks are the same size, we are done.

  }

  public void testFlatMap() {
    SpliteratorTester.of(
            () ->
                CollectSpliterators.flatMap(
                    Arrays.spliterator(new String[] {"abc", "", "de", "f", "g", ""}),
                    (String str) -> Lists.charactersOf(str).spliterator(),
                    Spliterator.SIZED | Spliterator.DISTINCT | Spliterator.NONNULL,
                    7))

          "pvt.k12.ca.us",
          "www.rave.ca.",
          "cnn.ca",
          "ledger-enquirer.com",
          "it-trace.ch",
          "cool.dk",
          "cool.co.uk",
          "cool.de",
          "cool.es",
          "cool\uFF61fr", // Alternate dot character
          "cool.nl",
          "members.blah.nl.",
          "cool.se",
          "utenti.blah.it",
          "kt.co",

        // make sure repeated entries are skipped
        Mirror mirrorA3 = newMirror("a", "a", "http://a3");

        Mirror mirrorB = newMirror("b", "b", "http://b");
        Mirror mirrorC = newMirror("c", "d,e", "http://de");
        Mirror mirrorC2 = newMirror("c", "*", "http://wildcard");
        Mirror mirrorC3 = newMirror("c", "e,f", "http://ef");

          "pvt.k12.ca.us",
          "www.rave.ca.",
          "cnn.ca",
          "ledger-enquirer.com",
          "it-trace.ch",
          "cool.dk",
          "cool.co.uk",
          "cool.de",
          "cool.es",
          "cool\uFF61fr", // Alternate dot character
          "cool.nl",
          "members.blah.nl.",
          "cool.se",
          "utenti.blah.it",
          "kt.co",

    }
    return !iterable.iterator().hasNext();
  }

  /**
   * Returns an iterable over the merged contents of all given {@code iterables}. Equivalent entries
   * will not be de-duplicated.
   *
   * <p>Callers must ensure that the source {@code iterables} are in non-descending order as this
   * method does not sort its input.
   *

coal?gngnauq?laig?ngnod??onah?rtgnauq??kalkad?m&an&ah?gnauq??oc?utnok??n&a&ehgn?gnol?kcab?uhthni&b?n???e&ibneid?y&gnuh?u&gniaht?hp????osgnal??o&fni?ht&nac?uhp??i?rp??pahtgnod?t&en?ni?opsgolb,?u&a&hcial?mac?tgnuv-airab??de?eilcab??vog?zib???wo&rc?t!epac????o&76i4orfy--nx?a!.&bp?de?go?oc?ti?vg??boat??b!.&a&ci&sum?tilop??i&c&arcomed?neic??golo&ce?ncet??m&edaca?onoce??rt&ap?sudni??vilob??n&egidni?icidem??serpme?tsiver?vitarepooc??b&ew?og??dulas?e&rbmon?tr&a?op&ed?snart????g&olb?ro??ikiw?l&a&noi&cani...

    /** The key of the configuration. e.g. ar=ar<br>
     * bg=bg<br>
     * bn=bn<br>
     * ca=ca<br>
     * ckb-iq=ckb-iq<br>
     * ckb_IQ=ckb-iq<br>
     * cs=cs<br>
     * da=da<br>
     * de=de<br>
     * el=el<br>
     * en=en<br>
     * en-ie=en-ie<br>
     * en_IE=en-ie<br>
     * es=es<br>
     * et=et<br>
     * eu=eu<br>
     * fa=fa<br>
     * fi=fi<br>
     * fr=fr<br>

    }
    return !iterable.iterator().hasNext();
  }

  /**
   * Returns an iterable over the merged contents of all given {@code iterables}. Equivalent entries
   * will not be de-duplicated.
   *
   * <p>Callers must ensure that the source {@code iterables} are in non-descending order as this
   * method does not sort its input.
   *

    return checkNotNull(iterator);
  }

  /**
   * Returns an iterator over the merged contents of all given {@code iterators}, traversing every
   * element of the input iterators. Equivalent entries will not be de-duplicated.
   *
   * <p>Callers must ensure that the source {@code iterators} are in non-descending order as this
   * method does not sort its input.
   *