code: public static String formatUnknownKey(String keyName) {
  
          StringBuffer buf = new StringBuffer(64);
          buf.append(UNKNOWN_KEY_EXTENSION);
          buf.append(" ");
          buf.append(keyName);
          buf.append(" ");
          buf.append(UNKNOWN_KEY_EXTENSION);
          return buf.toString();
      }
docs: Formats an unknown key.<p>
  
  @param keyName the key to format
  @return the formatted unknown key
  
  @see #isUnknownKey(String)