{"ast_node_type":"variable","tokens":[{"end":92,"kind":"keyword","start":0,"text":"let"}]}
            let tuple_type = self.structurally_resolve_type(call_span, formal_input_tys[0]);
        let (formal_input_tys, expected_input_tys) = if tuple_arguments == TupleArguments {
            match tuple_type.kind() {