pub async fn get_value(&mut self, key: &StorageKey) -> DalResult<H256> {
        let Some(l2_block_number) = self
            .storage
            .blocks_dal()
            .get_sealed_l2_block_number()
            .await?
        else {
            let err = Instrumented::new("get_value")
                .with_arg("key", &key)
                .constraint_error(anyhow::anyhow!("no sealed l2 blocks"));
            return Err(err);
        };
        self.get_historical_value_unchecked(key.hashed_key(), l2_block_number)
            .await
    }
Gets the current value for the specified `key`. Uses state of the latest sealed L2 block.
Returns error if there is no sealed L2 blocks.
core/lib/dal/src/storage_web3_dal.rs