def enable_mfa_device(self, user_name, serial_number,
                          auth_code_1, auth_code_2):
        """
        Enables the specified MFA device and associates it with the
        specified user.

        :type user_name: string
        :param user_name: The username of the user
        
        :type serial_number: string
        :param seriasl_number: The serial number which uniquely identifies
                               the MFA device.

        :type auth_code_1: string
        :param auth_code_1: An authentication code emitted by the device.

        :type auth_code_2: string
        :param auth_code_2: A subsequent authentication code emitted
                            by the device.

        """
        params = {'UserName' : user_name,
                  'SerialNumber' : serial_number,
                  'AuthenticationCode1' : auth_code_1,
                  'AuthenticationCode2' : auth_code_2}
        return self.get_response('EnableMFADevice', params)