code: func (s *Swap) loadState(peer *protocols.Peer) (err error) {
  	var peerBalance int64
  	peerID := peer.ID()
  	//only load if the current instance doesn't already have this peer's
  	//balance in memory
  	if _, ok := s.balances[peerID]; !ok {
  		err = s.stateStore.Get(peerID.String(), &peerBalance)
  		s.balances[peerID] = peerBalance
  	}
  	return
  }
docs: //load balances from the state store (persisted)