I have no idea how to do this red line picture
GridPane left = new GridPane();
root.setLeft(left);
left.setPadding(new Insets(10, 10, 10, 15));
Label l1=new Label("Panel plików");
left.addRow(0,l1);
left.setPrefSize(350, Double.MAX_VALUE);
Border b = new Border(new BorderStroke(Color.RED, BorderStrokeStyle.SOLID, CornerRadii.EMPTY, BorderWidths.DEFAULT));
left.setBorder(b);
Can you help me?