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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 update_device_info(self, device_id, display_name):
 """Update the display name of a device. Args: device_id (str):
 The device ID of the device to update. display_name (str):
 New display name for the device. """

        content = {
            "display_name": display_name
        }
        return self._send("PUT", "/devices/%s" % device_id, content=content)