button [] [] to node -- java : I'll keep it quick. I'm trying to create a standard calculator. I want to use a BorderPane so I can keep my display:

     TextField display = new TextField();
     pane.setTop(display); however I am using an array:
I then would want to use an array of buttons as a single object to place in the center of the pane.

     Button [][] keys = new Button [a][b];
     pane.setCenter(keys);
however I get an error: Button [][] cannot be converted to Node. I would like to know if there is anyway I can parse the elements to become/assume the value of a Node or if i can create a method to do so. 

Appreciate the help, thanks!
