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import { TreeNode } from "../binary-tree-inorder-traversal/TreeNode.ts";
function mergeTrees(    root1: TreeNode | null,    root2: TreeNode | null,): TreeNode | null {    if (!root1 && !root2) return null;    if (!root1) return root2;    if (!root2) return root1;    const root = new TreeNode(root1.val + root2.val);    root.left = mergeTrees(root1.left, root2.left);    root.right = mergeTrees(root1.right, root2.right);    return root;}export default mergeTrees;