$.extend(ElementNode.prototype, {
     nodeType: Node.ELEMENT_NODE,
 
-    setData: function(key, value) {
-        if(value !== undefined) {
-            this._$.data(key, value);
+    setData: function(arg1, arg2) {
+        if(arguments.length === 2) {
+            if(_.isUndefined(arg2)) {
+                this._$.removeData(arg1);
+            } else {
+                this._$.data(arg1, arg2);
+            }
         } else {
             this._$.removeData(_.keys(this._$.data()));
-            this._$.data(key);
+            this._$.data(arg1);
         }
     },