From 4bed69a9b956c5e09d0819bf253b51e4713a6c31 Mon Sep 17 00:00:00 2001
From: wuxiang <wuxiangzhou2010@gmail.com>
Date: Tue, 3 Apr 2018 17:40:21 +0800
Subject: [PATCH] add nil check

---
 stats.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/stats.go b/stats.go
index 3a8f33cc6..17bab8757 100644
--- a/stats.go
+++ b/stats.go
@@ -70,6 +70,8 @@ func (s *syncStatManager) Set(m StatManager) {
 	s.Lock()
 	defer s.Unlock()
 
-	s.StatManager.Close()
+	if s.StatManager != nil {
+		s.StatManager.Close()
+	}
 	s.StatManager = m
 }