syntax_data: {"ast_node_type":"variable","tokens":[{"end":89,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                         let ref_str_ty = Ty::new_imm_ref(tcx, re_erased, tcx.types.str_);
context_before:                         let re_erased = tcx.lifetimes.re_erased;
context_after:                         let ref_str = self.temp(ref_str_ty, test.span);