result = await fn()
                results.append(result)  # noqa: B023

            async with anyio.create_task_group() as tg:
                for sub_value in value:
                    tg.start_soon(process_fn, sub_value.read)
            value = serialize_sequence_value(field=field, value=results)
        if value is not None:
            values[get_validation_alias(field)] = value