// 3-9
//
// Check that a peer does nothing if it receives a promise with a wrong step.
This tests sends a prepare message to an acceptor. Then it checks whether the proposer has sent 2 messages:
// > proposer has broadcasted the paxos propose and sent to itself a
// promise.
I don't understand why the proposer would sent itself a promise. Doesn't that come from the acceptor?
Or do both nodes act as acceptors?
