pub fn tool_2<A, B, O, F>( f: impl Fn(A, B) -> F + Send + Sync + 'static, a: impl Argument<A> + Send + Sync + 'static, b: impl Argument<B> + Send + Sync + 'static, ) -> Tool<(), ()>where O: IntoResponse, O::Content: Serialize + Send, F: Future<Output = O> + Send + 'static,