root
 Video
  Terminator
  Batman
  Harry Potter
 Music
  Kendrick Lamar
  Oxxxymiron
  Lana Del Rey
 Pictures
  Comics
  Mona Lisa
  Picasso

package tree;

class SampleSearching {

	public static void main(String[] args) {
		
		Comparable<String> searchCriteria = new Comparable<String>() {
			@Override
			public int compareTo(String treeData) {
				if (treeData == null)
					return 1;
				boolean nodeOk = treeData.contains("node01");
				return nodeOk ? 0 : 1;
			}
		};

		TreeNode<String> treeRoot = Main.getSet1();
		TreeNode<String> found = treeRoot.findTreeNode(searchCriteria);

		System.out.println("Found: " + found);
	}

}

package tree;

class Main {

    public static void main(String[] args) {
        TreeNode<String> treeRoot = getSet1();
        
        printTree(treeRoot);
        
        /*for (TreeNode<String> node : treeRoot) {
            String indent = createIndent(node.getLevel());
            System.out.println(indent + node.data);
        }*/
    }

    public static void printTree(TreeNode<String> tree) {

??????????????????????????????????????????????????????????????- как здесь написать рекурсию чтобы все элементы дерева вывело на экран
        
    }
    
    private static String createIndent(int depth) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < depth; i++) {
            sb.append(' ');
        }
        return sb.toString();
    }

    public static TreeNode<String> getSet1() {
        TreeNode<String> root = new TreeNode<>("root");

        TreeNode<String> node0 = root.addChild("Video");
        TreeNode<String> node1 = root.addChild("Music");
        TreeNode<String> node2 = root.addChild("Pictures");

        TreeNode<String> node00 = node0.addChild("Terminator");
        TreeNode<String> node01 = node0.addChild("Batman");
        TreeNode<String> node02 = node0.addChild("Harry Potter");
        TreeNode<String> node03 = node1.addChild("Kendrick Lamar");
        TreeNode<String> node04 = node1.addChild("Oxxxymiron");
        TreeNode<String> node05 = node1.addChild("Lana Del Rey");
        TreeNode<String> node06 = node2.addChild("Comics");
        TreeNode<String> node07 = node2.addChild("Mona Lisa");
        TreeNode<String> node08 = node2.addChild("Picasso");
        
        
        TreeNode<String> node09 = node08.addChild("Picasso1");
        TreeNode<String> node10 = node08.addChild("Picasso2");

        return root;

    }
}