{"id":"closest-value-requires-non-null-root","text":"`closestValue` dereferences `root.val` on the first line with no null check; passing `root=None` raises `AttributeError`.","truth_value":"IN","source":"entries/2026/06/06/closest-binary-search-tree-value-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"closest-value-requires-non-null-root","truth_value":"IN","reason":"premise"}]}}