diff --git a/vendor/github.com/petar/GoLLRB/llrb/util.go b/vendor/github.com/petar/GoLLRB/llrb/util.go
new file mode 100644
index 0000000..63dbdb2
--- /dev/null
+++ b/vendor/github.com/petar/GoLLRB/llrb/util.go
@@ -0,0 +1,17 @@
+// Copyright 2010 Petar Maymounkov. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package llrb
+
+type Int int
+
+func (x Int) Less(than Item) bool {
+	return x < than.(Int)
+}
+
+type String string
+
+func (x String) Less(than Item) bool {
+	return x < than.(String)
+}