docs: public static String padLeft(String str, int totalChars, char ch) {
      if (str == null) {
        str = "null";
      }
      StringBuilder sb = new StringBuilder();
      for (int i = 0, num = totalChars - str.length(); i < num; i++) {
        sb.append(ch);
      }
      sb.append(str);
      return sb.toString();
    }