pub fn new(number: L2BlockNumber, timestamp: u64, prev_l2_block_hash: H256) -> Self {
        Self {
            number,
            timestamp,
            prev_l2_block_hash,
            txs_rolling_hash: H256::zero(),
        }
    }
Creates a new hasher with the specified params. This assumes a L2 block without transactions;
transaction hashes can be supplied using [`Self::push_tx_hash()`].
core/lib/types/src/block.rs