logging.go
func (logger *Logger) AddHandler(handler Handler) {
	logger.lock.Lock()
	logger.Handlers = append(logger.Handlers, handler)
	logger.flushBuffer()
	logger.lock.Unlock()
}
func (logger *Logger) AddHandler(handler Handler) {
	logger.lock.Lock()
	logger.Handlers = append(logger.Handlers, handler)
	logger.flushBuffer()
	logger.lock.Unlock()
}
func ( logger * Logger ) AddHandler ( handler Handler ) { logger . lock . Lock ( ) logger . Handlers = append ( logger . Handlers , handler ) logger . flushBuffer ( ) logger . lock . Unlock ( ) }
// AddHandler add new handler to current logger.
AddHandler add new handler to current logger .