Function two_pc_bench 

pub fn two_pc_bench<'a>(
    coordinator: &Process<'a, Coordinator>,
    participants: &Cluster<'a, Participant>,
    num_participants: usize,
    clients: &Cluster<'a, Client>,
    num_clients_per_node: Singleton<usize, Cluster<'a, Client>, Bounded>,
    client_aggregator: &Process<'a, Aggregator>,
    client_interval_millis: u64,
    aggregate_interval_millis: u64,
    print_results: impl FnOnce(BenchResult<Process<'a, Aggregator>>),
)