docs: public static String joinEscaped(String[] input, char separator, char echar, char[] special) {
          StringBuilder sb = new StringBuilder();
          char[] schars = new char[(special != null ? special.length : 0) + 1];
          if (special != null && special.length > 0) {
              System.arraycopy(special, 0, schars, 1, special.length);
          }
          schars[0] = separator;
          for (String s : input) {
              if (sb.length() > 0) {
                  sb.append(separator);
              }
              sb.append(escape(s, echar, schars));
          }
          return sb.toString();
      }