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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_speaker_info(self, refresh=False, timeout=None):
 """Get information about the Sonos speaker. Arguments: refresh(bool):
 Refresh the speaker info cache. timeout: How long to wait for the server to send data before giving up, as a float, or a `(connect timeout, read timeout)` tuple e.g. (3, 5). Default is no timeout. Returns: dict: Information about the Sonos speaker, such as the UID, MAC Address, and Zone Name. """

        if self.speaker_info and refresh is False:
            return self.speaker_info
        else:
            response = requests.get('http://' + self.ip_address +
                                    ':1400/xml/device_description.xml',
                                    timeout=timeout)
            dom = XML.fromstring(response.content)

        device = dom.find('{urn:schemas-upnp-org:device-1-0}device')
        if device is not None:
            self.speaker_info['zone_name'] = device.findtext(
                '{urn:schemas-upnp-org:device-1-0}roomName')

            # no zone icon in device_description.xml -> player icon
            self.speaker_info['player_icon'] = device.findtext(
                '{urn:schemas-upnp-org:device-1-0}iconList/'
                '{urn:schemas-upnp-org:device-1-0}icon/'
                '{urn:schemas-upnp-org:device-1-0}url'
            )

            self.speaker_info['uid'] = self.uid
            self.speaker_info['serial_number'] = device.findtext(
                '{urn:schemas-upnp-org:device-1-0}serialNum')
            self.speaker_info['software_version'] = device.findtext(
                '{urn:schemas-upnp-org:device-1-0}softwareVersion')
            self.speaker_info['hardware_version'] = device.findtext(
                '{urn:schemas-upnp-org:device-1-0}hardwareVersion')
            self.speaker_info['model_number'] = device.findtext(
                '{urn:schemas-upnp-org:device-1-0}modelNumber')
            self.speaker_info['model_name'] = device.findtext(
                '{urn:schemas-upnp-org:device-1-0}modelName')
            self.speaker_info['display_version'] = device.findtext(
                '{urn:schemas-upnp-org:device-1-0}displayVersion')

            # no mac address - extract from serial number
            mac = self.speaker_info['serial_number'].split(':')[0]
            self.speaker_info['mac_address'] = mac

            return self.speaker_info
        return None