diff --git a/SimpleLinkedList/src/solution/SimpleListTest90.java b/SimpleLinkedList/src/solution/SimpleListTest90.java
index 9580b62..a53a297 100644
--- a/SimpleLinkedList/src/solution/SimpleListTest90.java
+++ b/SimpleLinkedList/src/solution/SimpleListTest90.java
@@ -6,8 +6,9 @@ import org.junit.jupiter.api.BeforeEach;
 
 public abstract class SimpleListTest90 {
 
-	//ISimpleList<Integer> list;
+	ISimpleList<Integer> list;
 	ISimpleList<Node<Integer>> nodeList;
+	
 	protected Node<Integer> nodeNull = new Node<Integer>(null);
 	protected Node<Integer> node0 = new Node<Integer>(0);
 	protected Node<Integer> node1 = new Node<Integer>(1);
@@ -15,18 +16,13 @@ public abstract class SimpleListTest90 {
 	protected Node<Integer> node3 = new Node<Integer>(3);
 	protected Node<Integer> node4 = new Node<Integer>(4);
 	
-	protected ISimpleList<Integer> getInstance1() {
-		// TODO Auto-generated method stub
-		return null;
-	}
+	protected abstract ISimpleList<Integer> getInstance1();
 
-	protected ISimpleList<Node<Integer>> getInstance2() {
-		// TODO Auto-generated method stub
-		return null;
-	}
+	protected abstract ISimpleList<Node<Integer>> getInstance2();
 
 	@BeforeEach
 	void setUp() throws Exception{
+		list = getInstance1();
 		nodeList = getInstance2();
 	}