style: apply Checkstyle fixes

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/ui/gameui/CasinoGameUI.java

@@ -1,12 +1,11 @@
 package ch.unibas.dmi.dbis.cs108.casono.client.ui.gameui;
 
+import java.io.IOException;
 import javafx.application.Application;
 import javafx.fxml.FXMLLoader;
 import javafx.scene.Scene;
 import javafx.stage.Stage;
 
-import java.io.IOException;
-
 /**
  * Hauptklasse für das Casino-Spiel-UI.
  *
@@ -20,6 +19,9 @@ import java.io.IOException;
  */
 public class CasinoGameUI extends Application {
 
+    private static final int DEFAULT_WIDTH = 1200;
+    private static final int DEFAULT_HEIGHT = 800;
+
     /**
      * Startet die Haupt-Stage der Anwendung.
      *
@@ -28,11 +30,13 @@ public class CasinoGameUI extends Application {
      */
     @Override
     public void start(Stage stage) throws IOException {
-        FXMLLoader fxmlLoader = new FXMLLoader(CasinoGameUI.class.getResource("/ui-structure/casinogameui.fxml"));
+        FXMLLoader fxmlLoader =
-        Scene scene = new Scene(fxmlLoader.load(), 1200, 800);
+                new FXMLLoader(CasinoGameUI.class.getResource("/ui-structure/casinogameui.fxml"));
+        Scene scene = new Scene(fxmlLoader.load(), DEFAULT_WIDTH, DEFAULT_HEIGHT);
         stage.setTitle("Casono (GAME)");
 
-        stage.getIcons().add(new javafx.scene.image.Image(getClass().getResource("/images/logoinverted.png").toExternalForm()));
+        String iconPath = getClass().getResource("/images/logoinverted.png").toExternalForm();
+        stage.getIcons().add(new javafx.scene.image.Image(iconPath));
         stage.setScene(scene);
         stage.setFullScreen(true);
         stage.show();