addrbook.go
func (a *AddrBook) OnStart() error {
	a.BaseService.OnStart()
	a.loadFromFile(a.filePath)
	a.wg.Add(1)
	go a.saveRoutine()
	return nil
}
func (a *AddrBook) OnStart() error {
	a.BaseService.OnStart()
	a.loadFromFile(a.filePath)
	a.wg.Add(1)
	go a.saveRoutine()
	return nil
}
// OnStart implements Service.