assertThat(Chars.contains(ARRAY234, (char) 2)).isTrue();
    assertThat(Chars.contains(ARRAY234, (char) 3)).isTrue();
    assertThat(Chars.contains(ARRAY234, (char) 4)).isTrue();
  }

  public void testIndexOf() {
    assertThat(Chars.indexOf(EMPTY, (char) 1)).isEqualTo(-1);
    assertThat(Chars.indexOf(ARRAY1, (char) 2)).isEqualTo(-1);
    assertThat(Chars.indexOf(ARRAY234, (char) 1)).isEqualTo(-1);

    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));
      StringBuilder str = new StringBuilder();

        String result = Hexdump.toHexString(data);
        assertEquals(2048, result.length()); // 1024 bytes * 2 chars

        // Test partial conversion
        String partial = Hexdump.toHexString(data, 512, 256);
        assertEquals(512, partial.length()); // 256 bytes * 2 chars
        assertTrue(partial.startsWith("00010203")); // 512 % 256 = 0, so starts at 0
    }

   *
   * @since 14.0
   */
  public static String toLowerCase(CharSequence chars) {
    if (chars instanceof String) {
      return toLowerCase((String) chars);
    }
    char[] newChars = new char[chars.length()];
    for (int i = 0; i < newChars.length; i++) {
      newChars[i] = toLowerCase(chars.charAt(i));
    }
    return String.valueOf(newChars);
  }

  /**

   * tests are divided into three sections:
   * 1. Tests on a hardcoded dataset for chains starting with median(), quartiles(), and scale(10);
   * 2. Tests on hardcoded datasets include non-finite values for chains starting with scale(10);
   * 3. Tests on a mechanically generated dataset for chains starting with percentiles();
   * 4. Tests of illegal usages of the API.
   */

  /*

   * tests are divided into three sections:
   * 1. Tests on a hardcoded dataset for chains starting with median(), quartiles(), and scale(10);
   * 2. Tests on hardcoded datasets include non-finite values for chains starting with scale(10);
   * 3. Tests on a mechanically generated dataset for chains starting with percentiles();
   * 4. Tests of illegal usages of the API.
   */

  /*

      @Override
      public Hasher putUnencodedChars(CharSequence chars) {
        for (Hasher hasher : hashers) {
          hasher.putUnencodedChars(chars);
        }
        return this;
      }

      @Override
      public Hasher putString(CharSequence chars, Charset charset) {
        for (Hasher hasher : hashers) {
          hasher.putString(chars, charset);
        }
        return this;
      }

   * Reader#skip(long) skip} to the end of the stream, and return the total number of chars that
   * were skipped.
   *
   * <p>Note that for sources that implement {@link #lengthIfKnown} to provide a more efficient
   * implementation, it is <i>possible</i> that this method will return a different number of chars
   * than would be returned by reading all of the chars.
   *

   * Reader#skip(long) skip} to the end of the stream, and return the total number of chars that
   * were skipped.
   *
   * <p>Note that for sources that implement {@link #lengthIfKnown} to provide a more efficient
   * implementation, it is <i>possible</i> that this method will return a different number of chars
   * than would be returned by reading all of the chars.
   *

    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));
      StringBuilder str = new StringBuilder();