// Identical valid surrogate pairs.
    assertEquals(
        "abc\uD8AB\uDCAB", Strings.commonPrefix("abc\uD8AB\uDCABdef", "abc\uD8AB\uDCABxyz"));
    // Differing valid surrogate pairs.
    assertEquals("abc", Strings.commonPrefix("abc\uD8AB\uDCABdef", "abc\uD8AB\uDCACxyz"));
    // One invalid pair.

        assertOrder(X_GT_Y, "1-abc", "1-alpha");
        assertOrder(X_GT_Y, "1-abc", "1-beta");
        assertOrder(X_GT_Y, "1-abc", "1-milestone");
        assertOrder(X_GT_Y, "1-abc", "1-rc");
        assertOrder(X_GT_Y, "1-abc", "1-snapshot");
        assertOrder(X_GT_Y, "1-abc", "1");
        assertOrder(X_GT_Y, "1-abc", "1-sp");
    }

    @Test

    // Identical valid surrogate pairs.
    assertEquals(
        "abc\uD8AB\uDCAB", Strings.commonPrefix("abc\uD8AB\uDCABdef", "abc\uD8AB\uDCABxyz"));
    // Differing valid surrogate pairs.
    assertEquals("abc", Strings.commonPrefix("abc\uD8AB\uDCABdef", "abc\uD8AB\uDCACxyz"));
    // One invalid pair.

      String.valueOf(Character.MIN_LOW_SURROGATE),
      Character.MIN_LOW_SURROGATE + "xyz",
      "abc" + Character.MIN_LOW_SURROGATE,
      "abc" + Character.MIN_LOW_SURROGATE + "xyz",
      String.valueOf(Character.MAX_LOW_SURROGATE),
      Character.MAX_LOW_SURROGATE + "xyz",
      "abc" + Character.MAX_LOW_SURROGATE,
      "abc" + Character.MAX_LOW_SURROGATE + "xyz",
    };
    for (String s : BAD_STRINGS) {

      String.valueOf(Character.MIN_LOW_SURROGATE),
      Character.MIN_LOW_SURROGATE + "xyz",
      "abc" + Character.MIN_LOW_SURROGATE,
      "abc" + Character.MIN_LOW_SURROGATE + "xyz",
      String.valueOf(Character.MAX_LOW_SURROGATE),
      Character.MAX_LOW_SURROGATE + "xyz",
      "abc" + Character.MAX_LOW_SURROGATE,
      "abc" + Character.MAX_LOW_SURROGATE + "xyz",
    };
    for (String s : BAD_STRINGS) {

    assertEquals(java.util.Optional.of("abc"), Optional.toJavaUtil(Optional.of("abc")));
  }

  public void testToJavaUtil_instance() {
    assertEquals(java.util.Optional.empty(), Optional.absent().toJavaUtil());
    assertEquals(java.util.Optional.of("abc"), Optional.of("abc").toJavaUtil());
  }

  @SuppressWarnings("NullOptional")
  public void testFromJavaUtil() {

		},
	}, {
		maker: makeSparse{makeReg{3, "abc"}, sparseHoles{{0, 2}, {5, 2}}, 7},
		tests: []testFnc{
			testRemaining{7, 3},
			testWrite{"\x00\x00abc\x00\x00", 7, nil},
			testRemaining{0, 0},
		},
	}, {
		maker: makeSparse{makeReg{3, "abc"}, sparseHoles{{0, 2}, {5, 2}}, 7},
		tests: []testFnc{
			testRemaining{7, 3},
			testReadFrom{fileOps{int64(2), "abc", int64(1), "\x00"}, 7, nil},
			testRemaining{0, 0},

  }

  public void testEmptiesFirst() {
    Optional<String> empty = Optional.empty();
    Optional<String> abc = Optional.of("abc");
    Optional<String> z = Optional.of("z");

    Comparator<Optional<String>> comparator = emptiesFirst(comparing(String::length));
    testComparator(comparator, empty, z, abc);

    // Just demonstrate that no explicit type parameter is required

        assertEquals("abc", fessXpathTransformer.removeCommentTag("abc"));
        assertEquals("abc ", fessXpathTransformer.removeCommentTag("abc<!-- foo -->"));
        assertEquals("abc 123", fessXpathTransformer.removeCommentTag("abc<!-- fo\no -->123"));
        assertEquals("abc 123", fessXpathTransformer.removeCommentTag("abc<!--\n foo -->123"));

		{
			bucketNames[0], "asia", "asia/europe/", "abc", "", 0,
			ListMultipartsInfo{},
			fmt.Errorf("Invalid combination of uploadID marker '%s' and marker '%s'", "abc", "asia/europe/"), false,
		},
		{
			// Contains a base64 padding character
			bucketNames[0], "asia", "asia/europe", "abc=", "", 0,
			ListMultipartsInfo{},
			fmt.Errorf("Malformed upload id %s", "abc="), false,
		},