code: def _list_vlans_by_name(self, name):
          
          results = self.list_vlans(name=name, mask='id')
          return [result['id'] for result in results]
docs: Returns a list of IDs of VLANs which match the given VLAN name.
  
          :param string name: a VLAN name
          :returns: List of matching IDs