public MutableTree<T> removeSubtree(Node<T> rootSubTree) {
//        this.baseRemoveSubtree(this, rootSubTree);
//        return this;

        if (this.root == rootSubTree) {
            this.root = null;
            return null;
        }

        if (!root.getChildren().contains(rootSubTree)) {
            for (var child : root.getChildren()) {
                if (child.getChildren().size() == 0) {
                    return null;
                }
                removeSubtree(child);
            }
        } else {
            root.getChildren().remove(rootSubTree);
        }

        return this;
    }