unary invoke

        static Task<TResponse> Execute<TRequest, TResponse>(this Channel channel, TRequest request, string serviceName, string methodName,
            CallOptions options = default, string? host = null)
            where TRequest : class
            where TResponse : class
            => Execute<TRequest, TResponse>(new DefaultCallInvoker(channel), request, serviceName, methodName, options, host);
        static async Task<TResponse> Execute<TRequest, TResponse>(this CallInvoker invoker, TRequest request, string serviceName, string methodName,
            CallOptions options = default, string? host = null)
            where TRequest : class
            where TResponse : class
        {
            var method = new Method<TRequest, TResponse>(MethodType.Unary, serviceName, methodName,
                CustomMarshaller<TRequest>.Instance, CustomMarshaller<TResponse>.Instance);
            using (var auc = invoker.AsyncUnaryCall(method, host, options, request))
            {
                return await auc.ResponseAsync;
            }
        }
        class CustomMarshaller<T> : Marshaller<T>
        {
            public static readonly CustomMarshaller<T> Instance = new CustomMarshaller<T>();
            private CustomMarshaller() : base(Serialize, Deserialize) { }

            private static T Deserialize(byte[] payload)
            {
                using (var ms = new MemoryStream(payload))
                {
                    return ProtoBuf.Serializer.Deserialize<T>(ms);
                }
            }
            private static byte[] Serialize(T payload)
            {
                using (var ms = new MemoryStream())
                {
                    ProtoBuf.Serializer.Serialize<T>(ms, payload);
                    return ms.ToArray();
                }
            }
        }