syntax_data: {"ast_node_type":"variable","tokens":[{"end":29,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let mut scope = None;
context_before:     fn adjust(&self, ctxt: &mut SyntaxContext, expn_id: ExpnId) -> Option<ExpnId> {
context_after:         while !self.is_descendant_of(expn_id, self.outer_expn(*ctxt)) {