pub fn has_next(&self, filter: &L2TxFilter) -> bool {
        self.l1_transactions.contains_key(&self.next_priority_id)
            || self
                .l2_priority_queue
                .iter()
                .rfind(|el| el.matches_filter(filter))
                .is_some()
    }
Returns `true` if there is a transaction in the mempool satisfying the filter.
core/lib/mempool/src/mempool_store.rs