@Override
 public void max(final Positionable max) {
   for (int d = 0; d < max.numDimensions(); d++) {
     max.setPosition(position[d] + radius, d);
   }
 }
 @Override
 public void min(final Positionable min) {
   for (int d = 0; d < min.numDimensions(); d++) {
     min.setPosition(position[d] - radius, d);
   }
 }