How to get a ComboBox to use an Object's toString method instead of setting it as a graphic?

Question

I have a Station object that extends javafx.scene.shape.Ellipse:

public class Station extends Ellipse

And I am trying to put them into a javafx.scene.control.ComboBox and have that ComboBox use the toString() method of my Station objects instead of using them as a graphic.

 ComboBox<Station> metroStationComboBox = new ComboBox<>();
 //ADDS A HASHSET OF THE STATIONS
 metroStationComboBox.getItems().addAll(dataManager.getStations());

I made a cell factory which will use the toString() method when they are not selected, but as soon as you select one, it will take the object in as a graphic.:

metroStationComboBox.setCellFactory((ListView<Station> p) -> {
        return new ListCell<Station>(){
            @Override protected void updateItem(Station item, boolean empty) {
                super.updateItem(item, empty);
                if (!empty && item != null) {
                    setText(item.toString());
                    setGraphic(null);
                } else {
                    setText(null);
                }
            }

        };
    });

Is there a way to redefine the selection method so that I can have it use the toString method of Station?

(The above code has been reduced for clarity)