code: def test_node_depth():
      root = build_full_tree(3)
      assert root.node_depth == 0
      assert root.children[0].node_depth == 1
      assert root.children[0].children[0].node_depth == 2
  
imports: from orion.core.utils.tree import DepthFirstTraversal, PreOrderTraversal, TreeNode, flattened
label_desc: Use image node_id 25 for calling a global function with example usage: test_node_depth() without return types