diff --git a/vendor/github.com/modern-go/concurrent/log.go b/vendor/github.com/modern-go/concurrent/log.go
new file mode 100644
index 0000000..9756fcc
--- /dev/null
+++ b/vendor/github.com/modern-go/concurrent/log.go
@@ -0,0 +1,13 @@
+package concurrent
+
+import (
+	"os"
+	"log"
+	"io/ioutil"
+)
+
+// ErrorLogger is used to print out error, can be set to writer other than stderr
+var ErrorLogger = log.New(os.Stderr, "", 0)
+
+// InfoLogger is used to print informational message, default to off
+var InfoLogger = log.New(ioutil.Discard, "", 0)
\ No newline at end of file