Fix:add deprecated comment

getty.go

@@ -153,6 +153,10 @@ type Session interface {
 	SetReader(Reader)
 	SetWriter(Writer)
 	SetCronPeriod(int)
+
+	// Deprecated: don's use read queue.
+	SetRQLen(int)
+
 	SetWQLen(int)
 	SetWaitTime(time.Duration)
 	SetTaskPool(*TaskPool)

session.go

@@ -273,6 +273,9 @@ func (s *session) SetCronPeriod(period int) {
 	s.period = time.Duration(period) * time.Millisecond
 }
 
+// Deprecated: don's use read queue.
+func (s *session) SetRQLen(readQLen int) {}
+
 // set @session's Write queue size
 func (s *session) SetWQLen(writeQLen int) {
 	if writeQLen < 1 {