AB3: BodyForceTreeMap working

src/Simulation3.java

@@ -14,7 +14,7 @@ public class Simulation3 {
     public static void main(String[] args) {
         CodeDraw cd = new CodeDraw();
         BodyLinkedList bodies = new BodyLinkedList();
-        BodyForceMap forceOnBody = new BodyForceMap();
+        BodyForceTreeMap forceOnBody = new BodyForceTreeMap();
 
         Random random = new Random(2022);