syntax_data: {"ast_node_type":"variable","tokens":[{"end":64,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                 let data = self.typeck_results.offset_of_data();
context_before:             hir::ExprKind::OffsetOf(_, _) => {
context_after:                 let &(container, ref indices) = data.get(expr.hir_id).unwrap();