old_contents: """ Discovers Belkin Wemo devices. """
  
  from . import SSDPDiscoverable
  
  
  class Discoverable(SSDPDiscoverable):
      """ Adds support for discovering Belkin WeMo platform devices. """
  
      def info_from_entry(self, entry):
          """ Returns most important info from a uPnP entry. """
          device = entry.description['device']
  
          return (device['friendlyName'], device['modelName'],
                  entry.values['location'], device.get('macAddress', ''))
  
      def get_entries(self):
          """ Returns all Belkin Wemo entries. """
          return self.find_by_device_description(
              {'manufacturer': 'Belkin International Inc.'})
  
new_contents: """ Discovers Belkin Wemo devices. """
  
  from . import SSDPDiscoverable
  
  
  class Discoverable(SSDPDiscoverable):
      """ Adds support for discovering Belkin WeMo platform devices. """
  
      def info_from_entry(self, entry):
          """ Returns most important info from a uPnP entry. """
          device = entry.description['device']
  
          return (device['friendlyName'], device['modelName'],
                  entry.values['location'], device.get('macAddress', ''),
                  device['serialNumber'])
  
      def get_entries(self):
          """ Returns all Belkin Wemo entries. """
          return self.find_by_device_description(
              {'manufacturer': 'Belkin International Inc.'})
  
subject: Add serialnumber to wemo discovery info tuple