Sets the port that WebDriver will be running on

def port(self, port):
        """
        Sets the port that WebDriver will be running on
        """
        if not isinstance(port, int):
            raise WebDriverException("Port needs to be an integer")
        try:
            port = int(port)
            if port < 1 or port > 65535:
                raise WebDriverException("Port number must be in the range 1..65535")
        except (ValueError, TypeError):
            raise WebDriverException("Port needs to be an integer")
        self._port = port
        self.set_preference("webdriver_firefox_port", self._port)