Растягивание элементов в GridPane - Java

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.GridPane;
import javafx.stage.Stage;
 
public class Main extends Application {
 
    @Override
    public void start(Stage primaryStage) throws Exception{
        GridPane g = new GridPane();
        AnchorPane a1 = new AnchorPane();
        AnchorPane a2 = new AnchorPane();
        TextField t1 = new TextField();
        TextField t2 = new TextField();
 
        AnchorPane.setLeftAnchor(t1,0.0);
        AnchorPane.setRightAnchor(t1,0.0);
 
        AnchorPane.setLeftAnchor(t2,0.0);
        AnchorPane.setRightAnchor(t2,0.0);
 
        a1.getChildren().add(t1);
        a2.getChildren().add(t2);
 
        g.add(a1,0,0);
        g.add(a2,0,1);
 
        primaryStage.setTitle("Hello World");
        primaryStage.setScene(new Scene(g, 300, 275));
 
        g.setGridLinesVisible(true);
 
        primaryStage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}