syntax_data: {"ast_node_type":"other","tokens":[{"end":76,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     // like how `Predicate::kind` and `Region::kind` do. (It would result in
context_before:     // It would be nicer if this returned the value instead of a reference,
context_after:     // many fewer subsequent dereferences.) But that gives a small but