feat: adds an interface to the struct

generator.go

@@ -26,6 +26,10 @@ const (
 	customEpoch = 1420070400000
 )
 
+type SnowflakeGenerator interface {
+	NextID() int64
+}
+
 type SequenceGenerator struct {
 	mu            sync.Mutex
 	lastTimeStamp int64
@@ -57,7 +61,7 @@ func (s *SequenceGenerator) NextID() int64 {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
-	var currentTimestamp = timestamp()
+	currentTimestamp := timestamp()
 
 	if currentTimestamp < s.lastTimeStamp {
 		panic("system clock is destroyed")