Partly resolves "Implement state copy in AST"

eraser-base/src/test/java/de/tudresden/inf/st/eraser/ControllingItemTest.java

@@ -139,7 +139,11 @@ public class ControllingItemTest {
     assertEquals(4, item2.getState(), DELTA);
 
     item1.setState(5);
-    assertEquals(5, item1.getState(), DELTA);
+    assertEquals(5, item1.getState(), DELTA, "Item was not controlled correctly");
     assertEquals(5, item2.getState(), DELTA, "Item was not controlled correctly");
+
+    item2.setState(3);
+    assertEquals(3, item1.getState(), DELTA, "Item was not controlled correctly");
+    assertEquals(3, item2.getState(), DELTA, "Item was not controlled correctly");
   }
 }