diff --git a/lib/feature_extractor.js b/lib/feature_extractor.js
index d51b7149..0145413b 100644
--- a/lib/feature_extractor.js
+++ b/lib/feature_extractor.js
@@ -540,11 +540,6 @@ function parseFile(code, file) {
 	return toplevel;
 }
 
-function FakeSymbolDef(name, id) {
-    this.name = name;    
-    this.id = id;
-};
-
 function extendAst(root){
 	var current_id = 0;
 
@@ -565,14 +560,6 @@ function extendAst(root){
 		}
 
 		if (node instanceof AST_Symbol) {
-			// if (node.definition() == null && node instanceof AST_This){
-				// var scope = node;
-				// while (!(scope instanceof AST_Lambda) && scope.parent != null){
-				// 	scope = scope.parent;
-				// }
-				// var name = nodeToString(scope);
-				// node.thedef = new FakeSymbolDef(name + "_this", scope.id);				
-			// } else {
 			if (node.definition() != null) {
 				node.definition().id = current_id;
 				current_id++;