public void Repaint(World world) {
   
    for (int i = 0; i < world.getSize(); i++) {
      for (int j = 0; j < world.getSize(); j++) {
        if (world.getField()[i][j]) {
           (allButtons[i][j]).setBackground(Color.GREEN);
         } else {
           (allButtons[i][j]).setBackground(Color.BLACK);
         } // end else
      } // end for j
    } // end for i
  } // end Repaint method