add router handler & connector

observer/stats/wrapper/conn.go

@@ -25,7 +25,7 @@ type conn struct {
 }
 
 func WrapConn(c net.Conn, pStats stats.Stats) net.Conn {
-	if pStats == nil {
+	if c == nil || pStats == nil {
 		return c
 	}
 

observer/stats/wrapper/io.go

@@ -13,7 +13,7 @@ type readWriter struct {
 }
 
 func WrapReadWriter(rw io.ReadWriter, stats stats.Stats) io.ReadWriter {
-	if stats == nil {
+	if rw == nil || stats == nil {
 		return rw
 	}