Working on a Project but can' t see why is it not working. Creates rectangles underneath each other.

/*

• To change this license header, choose License Headers in Project Properties.
• To change this template file, choose Tools | Templates
• and open the template in the editor. */ package rectangleproject;

/**

• import the necessary packages / import java.awt.Font; import javafx.application.Application; import javafx.scene.; import javafx.stage.; import javafx.scene.Group; import javafx.scene.paint.; import javafx.scene.shape.*; import javafx.scene.text.Text;

/** *

• @author jonathanhector *

• creates the scene and scene Title * */ public abstract class RectangleProject extends Application {

  private Shape rect1; private Shape rect2; Group secondaryGroup = new Group(rect1, rect2); private Object shapeBehavior;

  private void setScene(Stage stage) { Group rootNode = new Group(); Scene scene = new Scene(rootNode, 600, 800);

  /**
   * Creates the rectangles and gives it its dimensions. This part fills
   * the rectangles with Light Grey color.
   */
  rect1 = new Rectangle(10, 10, 40, 50);
  rect1.setFill(Color.LIGHTGREY);
  rect1.setStroke(Color.WHITE);
  
  rect2 = new Rectangle(20, 35, 40, 50);
  rect2.setFill(Color.LIGHTGREY);
  rect2.setStroke(Color.WHITE);
  
  /**
   * call the new scene and creates the rect1 and rect2
   */
  secondaryGroup.getChildren().add(rect1);
  secondaryGroup.getChildren().add(rect2);
  
  rootNode.getChildren().add(secondaryGroup);
  
  stage.setScene(scene);
  stage.setTitle("Two Rectangles Not Behaving!!!");
  stage.show();
  

  }

  /**

  • determines the behavior of the rectangles */

  private void shapeBehavior(){

  Shape rect3 = Shape.union(rect1,rect2);
  rect3.setFill(Color.YELLOWGREEN);
  
  rect3  = Shape.intersect(rect1,rect2);
  rect3.setFill(Color.VIOLET);
  
  rect3 = Shape.subtract(rect1,rect2);
  rect3.setFill(Color.ORANGE);
  

  }

  /** *

  • @return the header for each diagram */

  public String header() {

  Text title1 = new Text(20, 5, "Sets intersection");
  title1.setFont(new Font(24));
  title1.setTextOrigin(VPos.TOP);
  rootNode.getChildren().add(title1);
  
  Text title2 = new Text(20, 5, "Sets union");
  title2.setFont(new Font(24));
  title2.setTextOrigin(VPos.MIDDLE);
  rootNode.getChildren().add(title2);
  
  Text title3 = new Text(20, 5, "Sets symmetrical difference");
  title3.setFont(new Font(24));
  title3.setTextOrigin(VPos.BOTTOM);
  rootNode.getChildren().add(title3);
  

  }

  public static void main(String[] args) {

  Application.launch(args);
  

  }

}