code: private static Boolean hasSwitch(String key, String sign) {
      return (key.length() > sign.length()) && key.substring(0, sign.length()).equals(sign);
    }
docs: Determines whether given argument key contains given argument sign.
  
  @param key  the argument key to check
  @param sign the sign to check for
  @return true if key contains sign as first characters, false otherwise
  @see OperaArgumentSign