syntax_data: {"ast_node_type":"variable","tokens":[{"end":73,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:             let mut self_normalized = data.normalize_to_macros_2_0(self);
context_before:         HygieneData::with(|data| {
context_after:             data.adjust(&mut self_normalized, expn_id);