diff --git a/lec7_lists4/DIY/AList.java b/lec7_lists4/DIY/AList.java
index eda0587..3df4b36 100755
--- a/lec7_lists4/DIY/AList.java
+++ b/lec7_lists4/DIY/AList.java
@@ -7,6 +7,7 @@
 public class AList {
     /** Creates an empty list. */
     public AList() {
+        List
     }
 
     /** Inserts X into the back of the list. */
@@ -32,4 +33,4 @@ public int size() {
     public int removeLast() {
         return 0;
     }
-} 
\ No newline at end of file
+}