code: func (ps *peerState) forAllOutboundPeers(closure func(sp *ServerPeer)) {
  	for _, e := range ps.outboundPeers {
  		closure(e)
  	}
  	for _, e := range ps.persistentPeers {
  		closure(e)
  	}
  }
docs: // forAllOutboundPeers is a helper function that runs closure on all outbound
  // peers known to peerState.