Function transaction_marker_equal_epoch_fenced 

pub fn transaction_marker_equal_epoch_fenced(
    transaction_version: i16,
    producer_epoch: i16,
    current_producer_epoch: i16,
    has_pending_transaction: bool,
) -> bool

Transaction version 2 requires an epoch bump for a pending transaction’s marker, except at the final marker epoch. Completed retries remain allowed.