EvictingQueue<String> queue = EvictingQueue.create(0);
    assertEquals(0, queue.size());

    assertTrue(queue.add("hi"));
    assertEquals(0, queue.size());

    assertTrue(queue.offer("hi"));
    assertEquals(0, queue.size());

    assertFalse(queue.remove("hi"));
    assertEquals(0, queue.size());

    try {
      queue.element();
      fail();
    } catch (NoSuchElementException expected) {

   * Asserts that a Unicode escaper escapes the given hi/lo surrogate pair into the expected string.
   *
   * @param escaper the non-null escaper to test
   * @param expected the expected output string
   * @param hi the high surrogate pair character
   * @param lo the low surrogate pair character
   */
  public static void assertUnicodeEscaping(
      UnicodeEscaper escaper, String expected, char hi, char lo) {

   * Asserts that a Unicode escaper escapes the given hi/lo surrogate pair into the expected string.
   *
   * @param escaper the non-null escaper to test
   * @param expected the expected output string
   * @param hi the high surrogate pair character
   * @param lo the low surrogate pair character
   */
  public static void assertUnicodeEscaping(
      UnicodeEscaper escaper, String expected, char hi, char lo) {

     * @param low
     *            最小の文字コード
     * @param hi
     *            最大の文字コード
     */
    protected static void whitespaceChars(final byte[] ctype2, int low, int hi) {
        if (low < 0) {
            low = 0;
        }
        if (hi >= ctype2.length) {
            hi = ctype2.length - 1;
        }
        while (low <= hi) {
            ctype2[low++] = CT_WHITESPACE;
        }
    }

                .put('\uD800', "<hi>".toCharArray())
                .put('\uDC00', "<lo>".toCharArray())
                .buildOrThrow());
    UnicodeEscaper unicodeEscaper = Escapers.asUnicodeEscaper(charEscaper);
    EscaperAsserts.assertBasic(unicodeEscaper);
    assertEquals("<hello><hi><lo>", charEscaper.escape("x\uD800\uDC00"));
    assertEquals("<hello><hi><lo>", unicodeEscaper.escape("x\uD800\uDC00"));

    EvictingQueue<String> queue = EvictingQueue.create(0);
    assertEquals(0, queue.size());

    assertTrue(queue.add("hi"));
    assertEquals(0, queue.size());

    assertTrue(queue.offer("hi"));
    assertEquals(0, queue.size());

    assertFalse(queue.remove("hi"));
    assertEquals(0, queue.size());

    try {
      queue.element();
      fail();
    } catch (NoSuchElementException expected) {

    // into the range of surrogate characters, but if they do we must not test
    // any values in that range. To see why, consider the case where:
    // safeMin <= {hi,lo} <= safeMax
    // where {hi,lo} are characters forming a surrogate pair such that:
    // codePointOf(hi, lo) > safeMax
    // which would result in the surrogate pair being (wrongly) considered safe.
    // If we clip the safe range used during the per-character tests so it is

                .put('\uD800', "<hi>".toCharArray())
                .put('\uDC00', "<lo>".toCharArray())
                .buildOrThrow());
    UnicodeEscaper unicodeEscaper = Escapers.asUnicodeEscaper(charEscaper);
    EscaperAsserts.assertBasic(unicodeEscaper);
    assertEquals("<hello><hi><lo>", charEscaper.escape("x\uD800\uDC00"));
    assertEquals("<hello><hi><lo>", unicodeEscaper.escape("x\uD800\uDC00"));

    char c = 0;
    for (int hi = 0; hi < 256; hi++) {
      for (int lo = 0; lo < 256; lo++) {
        char result = Chars.fromByteArray(new byte[] {(byte) hi, (byte) lo});
        assertWithMessage(
                String.format(
                    Locale.ROOT,
                    "hi=%s, lo=%s, expected=%s, result=%s",
                    hi,
                    lo,
                    (int) c,

    char c = 0;
    for (int hi = 0; hi < 256; hi++) {
      for (int lo = 0; lo < 256; lo++) {
        char result = Chars.fromByteArray(new byte[] {(byte) hi, (byte) lo});
        assertWithMessage(
                String.format(
                    Locale.ROOT,
                    "hi=%s, lo=%s, expected=%s, result=%s",
                    hi,
                    lo,
                    (int) c,