syntax_data: {"ast_node_type":"other","tokens":[{"end":60,"kind":"keyword","start":0,"text":"//"}]}
source_snippet: // with a certain amount of redundancy in them. For example,
context_before: // This explains why `HygieneData`, `SyntaxContext` and `ExpnId` have interfaces
context_after: // `SyntaxContext::outer_expn_data` combines `SyntaxContext::outer` and