pub async fn get_sealed_l1_batch_number(&mut self) -> DalResult<Option<L1BatchNumber>> {
        let row = sqlx::query!(
            r#"
            SELECT
                MAX(number) AS "number"
            FROM
                l1_batches
            WHERE
                is_sealed
            "#
        )
        .instrument("get_sealed_l1_batch_number")
        .report_latency()
        .fetch_one(self.storage)
        .await?;

        Ok(row.number.map(|num| L1BatchNumber(num as u32)))
    }
Returns the number of the last sealed L1 batch present in the DB, or `None` if there are no L1 batches.
core/lib/dal/src/blocks_dal.rs