1 files changed, 2 insertions, 1 deletions
diff --git a/src/client/model/diff.js b/src/client/model/diff.js
index 87fb03dd..4ad0d169 100644
--- a/src/client/model/diff.js
+++ b/src/client/model/diff.js
@@ -180,5 +180,6 @@ define([],
                 new_attr_diff : new_attr_diff,
                 new_vis_diff : new_vis_diff,
                 new_diff_set : new_diff_set,
+                is_attr_diff: function (obj) { return obj instanceof Attr_Diff; },
             }
-        });
-\ No newline at end of file
+        });