}
      }
      return chars.subSequence(0, l + 1);
    }

    @Override
    public boolean canDecode(CharSequence chars) {
      checkNotNull(chars);
      chars = trimTrailingPadding(chars);
      if (!alphabet.isValidPaddingStartPosition(chars.length())) {
        return false;
      }
      for (int i = 0; i < chars.length(); i++) {
        if (!alphabet.canDecode(chars.charAt(i))) {
          return false;

    public List<Character> create(Character[] elements) {
      char[] chars = Chars.toArray(asList(elements));
      return charactersOf(String.copyValueOf(chars));
    }
  }

  public static class CharactersOfCharSequenceGenerator extends TestCharacterListGenerator {
    @Override
    public List<Character> create(Character[] elements) {
      char[] chars = Chars.toArray(asList(elements));

    Set<Character> positive = Sets.newHashSetWithExpectedSize(chars.length);
    for (char c : chars) {
      positive.add(c);
    }
    for (int c = 0; c <= Character.MAX_VALUE; c++) {
      assertFalse(positive.contains(Character.valueOf((char) c)) ^ m.matches((char) c));
    }
  }

  static char[] randomChars(Random rand, int size) {
    Set<Character> chars = new HashSet<>(size);

    public List<Character> create(Character[] elements) {
      char[] chars = Chars.toArray(asList(elements));
      return charactersOf(String.copyValueOf(chars));
    }
  }

  public static class CharactersOfCharSequenceGenerator extends TestCharacterListGenerator {
    @Override
    public List<Character> create(Character[] elements) {
      char[] chars = Chars.toArray(asList(elements));

      while (i + 4 <= utf16Length) {
        char c0 = input.charAt(i);
        char c1 = input.charAt(i + 1);
        char c2 = input.charAt(i + 2);
        char c3 = input.charAt(i + 3);
        if (c0 < 0x80 && c1 < 0x80 && c2 < 0x80 && c3 < 0x80) {
          int k1 = c0 | (c1 << 8) | (c2 << 16) | (c3 << 24);
          k1 = mixK1(k1);
          h1 = mixH1(h1, k1);
          i += 4;

          protected void handleLine(String line, String end) {
            lines.add(line + end);
          }
        };
    char[] chars = input.toCharArray();
    int off = 0;
    while (off < chars.length) {
      int len = min(chars.length, off + chunk) - off;
      lineBuf.add(chars, off, len);
      off += len;
    }
    lineBuf.finish();
    return lines;
  }

            + "1234567890";
    assertThat(xmlEscaper.escape(s)).isEqualTo(s);

    // Test ASCII control characters.
    for (char ch = 0; ch < 0x20; ch++) {
      if (ch == '\t' || ch == '\n' || ch == '\r') {
        // Only these whitespace chars are permitted in XML,
        if (shouldEscapeWhitespaceChars) {
          assertEscaping(xmlEscaper, "&#x" + Integer.toHexString(ch).toUpperCase() + ";", ch);

      actual += expected;
    }
    assertEquals(EXPECTED_FOUR_BYTE_ROUNDTRIPPABLE_COUNT, actual);
  }

  private static String newString(char... chars) {
    return new String(chars);
  }

  private static byte[] toByteArray(int... bytes) {
    byte[] realBytes = new byte[bytes.length];
    for (int i = 0; i < bytes.length; i++) {
      realBytes[i] = (byte) bytes[i];

            + "1234567890";
    assertThat(xmlEscaper.escape(s)).isEqualTo(s);

    // Test ASCII control characters.
    for (char ch = 0; ch < 0x20; ch++) {
      if (ch == '\t' || ch == '\n' || ch == '\r') {
        // Only these whitespace chars are permitted in XML,
        if (shouldEscapeWhitespaceChars) {
          assertEscaping(xmlEscaper, "&#x" + Integer.toHexString(ch).toUpperCase() + ";", ch);

  }

  public void testCharsIgnored() {
    for (char c : IGNORED.toCharArray()) {
      String str = String.valueOf(c);
      assertEquals(str, c, Ascii.toLowerCase(c));
      assertEquals(str, c, Ascii.toUpperCase(c));
      assertFalse(str, Ascii.isLowerCase(c));
      assertFalse(str, Ascii.isUpperCase(c));
    }
  }

  public void testCharsLower() {
    for (char c : LOWER.toCharArray()) {
      String str = String.valueOf(c);