// utility method to set mark on board in event-dispatch thread
private void setMark(final Square squareToMark, final String mark) {
// SwingUtilities.invokeLater(new Runnable() {
// public void run() {
squareToMark.setMark(mark); // set mark in square
// } // end method run
// } // end anonymous inner class
// ); // end call to SwingUtilities.invokeLater
} // end method setMark
