void addNext(Node<T> n){
  nextNodes.add(n);
  Collections.sort(nextNodes,isVertical ? verticalComparator : horizontalComparator);
}

void addNext ( Node < T > n ) { nextNodes . add ( n ) ; Collections . sort ( nextNodes , isVertical ? verticalComparator : horizontalComparator ) ; }
adds a " next " node ( node to the right or bottom ) to this divider ' s list of next nodes .
