From b9b4805fed46c17bdc3d3349e03b2332f59daf08 Mon Sep 17 00:00:00 2001
From: Mario Uher <uher.mario@gmail.com>
Date: Sun, 30 Mar 2014 22:31:27 +0200
Subject: [PATCH] Requires active_support/concern in tree.rb.

---
 lib/mongoid/tree.rb | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/mongoid/tree.rb b/lib/mongoid/tree.rb
index 55efa6b..13544b2 100644
--- a/lib/mongoid/tree.rb
+++ b/lib/mongoid/tree.rb
@@ -1,3 +1,5 @@
+require 'active_support/concern'
+
 module Mongoid
   ##
   # = Mongoid::Tree