syntax_data: {"ast_node_type":"variable","tokens":[{"end":71,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                         let ref_str = self.temp(ref_str_ty, test.span);
context_before:                         let ref_str_ty = Ty::new_imm_ref(tcx, re_erased, tcx.types.str_);
context_after:                         let eq_block = self.cfg.start_new_block();