formatting

src/main/java/de/tudresden/inf/st/sample/callback/FeedbackHandler.java

@@ -25,7 +25,7 @@ public class FeedbackHandler extends AbstractHandler{
             print("Successfully sorted object " + object + " with color " + color);
         } else {
             print("Failed to sort object " + object);
-            result.getErrorList().forEach(err -> print(err));
+            result.getErrorList().forEach(this::print);
         }
 
         tokens.subList(1, tokens.size()).clear();