1 files changed, 4 insertions, 0 deletions
diff --git a/lib/tree.js b/lib/tree.js
index 07a6242b..204d10f4 100644
--- a/lib/tree.js
+++ b/lib/tree.js
@@ -15,6 +15,10 @@ var tree = {
     },
 
     createTree: function (depth, width, obj) {
+        depth = depth || 0;
+        width = width || 0;
+        obj = obj || {};
+
         if (!obj) {
             throw {
                 name: "ObjectError",