Returns firmware version.

        Args:
            None

        Returns:
            Dictionary

        Raises:
            None

def firmware_version(self):
        """
        Returns firmware version.

        Args:
            None

        Returns:
            Dictionary

        Raises:
            None
        """
        namespace = "urn:brocade.com:mgmt:brocade-firmware-ext"

        request_ver = ET.Element("show-firmware-version", xmlns=namespace)

        ver = self._callback(request_ver, handler='get')
        return ver.find('.//*{%s}os-version' % namespace).text