addrbook.go
func (a *AddrBook) AddAddress(addr *NetAddress, src *NetAddress) {
	a.mtx.Lock()
	defer a.mtx.Unlock()
	log.Info("Add address to book", "addr", addr, "src", src)
	a.addAddress(addr, src)
}
func (a *AddrBook) AddAddress(addr *NetAddress, src *NetAddress) {
	a.mtx.Lock()
	defer a.mtx.Unlock()
	log.Info("Add address to book", "addr", addr, "src", src)
	a.addAddress(addr, src)
}
// NOTE: addr must not be nil