syntax_data: {"ast_node_type":"other","tokens":[{"end":45,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     // many times, and rechecking many nodes.
context_before:     // the root (most of them do) and saves us from retracing many sub-paths
context_after:     lint_level_roots_cache: GrowableBitSet<hir::ItemLocalId>,