code: def get_boolean(self, name):
          
          for interface in self.all_interfaces:
              if isinstance(interface, VlanInterface):
                  if any(vlan for vlan in interface.interfaces
                         if getattr(vlan, name)):
                      return True
              else:
                  if getattr(interface, name):
                      return True
          return False
docs: Get the boolean value for attribute specified from the
          sub interface/s.