private void deleteCase4(RBTreeNode<K,V> node) {
        //If sibling's tree has longer black paths
        if(nodeColor(node.parent) == Color.RED &&
                nodeColor(node.sibling()) == Color.BLACK &&
                nodeColor(node.sibling().left) == Color.BLACK &&
                nodeColor(node.sibling().right) == Color.BLACK) {
            //Color sibling red
            node.sibling().color = Color.RED;
            //And parent black
            node.parent.color = Color.BLACK;
            //This should make the black paths property true again
        } else {
            deleteCase5(node);
        }
    }