Using existing function for testing

eraser-base/src/main/java/de/tudresden/inf/st/eraser/util/TestUtils.java

@@ -2,6 +2,8 @@ package de.tudresden.inf.st.eraser.util;
 
 import de.tudresden.inf.st.eraser.jastadd.model.*;
 
+import java.util.ArrayList;
+
 /**
  * Helper class to create models used in tests.
  *
@@ -37,9 +39,7 @@ public class TestUtils {
 
   public static SmartHomeEntityModel createModelWithGroup() {
     Root root = Root.createEmptyRoot();
-    Group g = new Group();
-    root.getSmartHomeEntityModel().addGroup(g);
-    g.setID("DEFAULT_GROUP");
+    ParserUtils.createUnknownGroup(root.getSmartHomeEntityModel(),new ArrayList<>());
 
     return root.getSmartHomeEntityModel();
   }