code: async def container_val(self, elem, container_type, params=None):
          
          if hasattr(container_type, 'boost_serialize'):
              raise ValueError('not supported')
  
          if self.writing:
              elem_type = params[0] if params else None
              if elem_type is None:
                  elem_type = container_type.ELEM_TYPE
  
              await self.dump_field(elem, elem_type, params[1:] if params else None)
  
          else:
              raise ValueError('Not supported')
docs: Single cont value
          :param elem:
          :param container_type:
          :param params:
          :param field_archiver:
          :return: