syntax_data: {"ast_node_type":"variable","tokens":[{"end":62,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let data = &self.syntax_context_data[ctxt.0 as usize];
context_before:     fn outer_mark(&self, ctxt: SyntaxContext) -> (ExpnId, Transparency) {
context_after:         (data.outer_expn, data.outer_transparency)