/**
   * Returns a copy of the input string in which all {@linkplain #isUpperCase(char) uppercase ASCII
   * characters} have been converted to lowercase. All other characters are copied without
   * modification.
   */
  public static String toLowerCase(String string) {
    int length = string.length();
    for (int i = 0; i < length; i++) {
      if (isUpperCase(string.charAt(i))) {
        char[] chars = string.toCharArray();

      assertFalse(str, Ascii.isUpperCase(c));
    }
  }

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

  public void testCharsUpper() {

  /**
   * Returns a copy of the input string in which all {@linkplain #isUpperCase(char) uppercase ASCII
   * characters} have been converted to lowercase. All other characters are copied without
   * modification.
   */
  public static String toLowerCase(String string) {
    int length = string.length();
    for (int i = 0; i < length; i++) {
      if (isUpperCase(string.charAt(i))) {
        char[] chars = string.toCharArray();

        if (isEmpty(name)) {
            return name;
        }
        final char[] chars = name.toCharArray();
        if (chars.length >= 2 && Character.isUpperCase(chars[0]) && Character.isUpperCase(chars[1])) {
            return name;
        }
        chars[0] = Character.toLowerCase(chars[0]);
        return new String(chars);
    }

    /**

  @Deprecated
  public static CharMatcher javaLetterOrDigit() {
    return JavaLetterOrDigit.INSTANCE;
  }

  /**
   * Determines whether a BMP character is upper case according to {@linkplain
   * Character#isUpperCase(char) Java's definition}.
   *
   * @deprecated Some uppercase characters are supplementary characters; see the class
   *     documentation.
   * @since 19.0 (since 1.0 as constant {@code JAVA_UPPER_CASE})
   */

        if (Ascii.isLowerCase(c)) {
          return true;
        }
      }
      return false;
    }

    private boolean hasUpperCase() {
      for (char c : chars) {
        if (Ascii.isUpperCase(c)) {
          return true;
        }
      }
      return false;
    }

    Alphabet upperCase() {
      if (!hasLowerCase()) {
        return this;
      }