EXPLAIN PLEASE - I understand the countnodes function - when is it called? what does return CountNodes (root) do?

ntNodes (TreeNode' tree): int TreeType: :GetLength() const 1ls the recursive function CountNodes to count the ll nodes in the tree return CountNodes (root); int CountNodes (TreeNode* tree) I/ Post: Returns the number of nodes in the tree. if (tree-NULL) return 0; else return CountNodes (tree->left) CountNodes (tree-right) + 1: Function GetItem chanter we demonstrated how to search for an elenme ot Ifit is not