pub fn trim_start(&mut self, trim_up_to: L1BatchNumber) {
        let Some(first_diff_batch_number) = self.first_diff_l1_batch_number else {
            return;
        };

        if first_diff_batch_number < trim_up_to {
            let split_at = (trim_up_to.0 - first_diff_batch_number.0) as usize;
            self.diffs = self.diffs.split_off(split_at);
            if self.diffs.is_empty() {
                self.first_diff_l1_batch_number = None;
            } else {
                self.first_diff_l1_batch_number = Some(trim_up_to);
            }
        }
    }
Trims diffs that correspond to batches with number less than `trim_up_to`. Does nothing if there are no.
core/lib/state/src/storage_factory/rocksdb_with_memory.rs