{"ast_node_type":"variable","tokens":[{"end":66,"kind":"keyword","start":0,"text":"let"}]}
        let self_ty = self.tcx.type_of(id).instantiate_identity();
        let item_span = self.tcx.def_span(id);
        let mut self_ty = self.tcx.peel_off_free_alias_tys(self_ty);