code: 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);
    }
docs: Returns a copy of the input character sequence in which all {@linkplain #isUpperCase(char)
  uppercase ASCII characters} have been converted to lowercase. All other characters are copied
  without modification.
  
  @since 14.0