code: def _interface_to_service(iface):
      '''
      returns the coresponding service to given interface if exists, otherwise return None
      '''
      for _service in _get_services():
          service_info = pyconnman.ConnService(os.path.join(SERVICE_PATH, _service))
          if service_info.get_property('Ethernet')['Interface'] == iface:
              return _service
      return Nonf _interface_to_service(iface):
      '''
      returns the coresponding service to given interface if exists, otherwise return None
      '''
      for _service in _get_services():
          service_info = pyconnman.ConnService(os.path.join(SERVICE_PATH, _service))
          if service_info.get_property('Ethernet')['Interface'] == iface:
              return _service
      return None
docs: returns the coresponding service to given interface if exists, otherwise return None