syntax_data: {"ast_node_type":"other","tokens":[{"end":57,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                 // heads and the provisional cache entry.
context_before:                 // kinds won't change, no matter the goals between these
context_after:                 if heads.iter().any(|(_, p)| matches!(p, AllPathsToHeadCoinductive::No)) {