Function libpijul::pristine::last_common_state

pub fn last_common_state<T: ChannelTxnT>(
    txn: &T, 
    c0: &T::Channel, 
    c1: &T::Channel
) -> Result<(u64, u64, Merkle), TxnErr<T::GraphError>>

Find the last state of c1 that is also in c0.