peer.go
func (p *Peer) NumConnections() (inbound int, outbound int) {
	p.RLock()
	inbound = len(p.inboundConnections)
	outbound = len(p.outboundConnections)
	p.RUnlock()
	return inbound, outbound
}
func (p *Peer) NumConnections() (inbound int, outbound int) {
	p.RLock()
	inbound = len(p.inboundConnections)
	outbound = len(p.outboundConnections)
	p.RUnlock()
	return inbound, outbound
}
// NumConnections returns the number of inbound and outbound connections for this peer.