}

  /**
   * If the argument is a {@linkplain #isLowerCase(char) lowercase ASCII character}, returns the
   * uppercase equivalent. Otherwise returns the argument.
   */
  public static char toUpperCase(char c) {
    return isLowerCase(c) ? (char) (c ^ CASE_MASK) : c;
  }

  /**
   * Indicates whether {@code c} is one of the twenty-six lowercase ASCII alphabetic characters

  }

  /**
   * If the argument is a {@linkplain #isLowerCase(char) lowercase ASCII character}, returns the
   * uppercase equivalent. Otherwise returns the argument.
   */
  public static char toUpperCase(char c) {
    return isLowerCase(c) ? (char) (c ^ CASE_MASK) : c;
  }

  /**
   * Indicates whether {@code c} is one of the twenty-six lowercase ASCII alphabetic characters