code: func (p *Peer) VerAckReceived() bool {
  	p.flagsMtx.Lock()
  	verAckReceived := p.verAckReceived
  	p.flagsMtx.Unlock()
  
  	return verAckReceived
  }
docs: // VerAckReceived returns whether or not a verack message was received by the
  // peer.
  //
  // This function is safe for concurrent access.