{"id":"treenode-shared-definition-in-preorder","text":"`TreeNode` defined in `binary-tree-preorder-traversal/solution.py` is imported by 400+ test files across the repo, making it the de facto shared binary tree node class — changes to its constructor signature are breaking.","truth_value":"IN","source":"entries/2026/06/06/binary-tree-preorder-traversal-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":["de-facto-treenode-infra-efficient"],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"treenode-shared-definition-in-preorder","truth_value":"IN","reason":"premise"}]}}