title: Unable to Pos.CENTER in BorderPane
body: <pre><code>    BorderPane root = new BorderPane();
  
      Button chooseFile = new Button("chooseFile");
      TextField fileLocation = new TextField("C:/");
      Button makeGrid = new Button("Solve");
      HBox fileLoad = new HBox(chooseFile, fileLocation, makeGrid);
  
      root.setTop(lastfil);
      BorderPane.setAlignment(root, Pos.TOP_CENTER);
      BorderPane.setMargin(root, new Insets(12,12,12,12));
      root.setPrefSize(500, 500);
  </code></pre>
  
  <p>I'm having some issues centering this, I want the prefSize to be 500 x 500 and have the file loader top center, but it does not do that. It is top but I am unable to get it to the center of the top. Anything obvious I'm doing wrong?</p>