Function actix_service::new_apply_fn

pub fn new_apply_fn<T, F, In, Out, U>(
    service: U, 
    f: F
) -> ApplyNewService<T, F, In, Out> where
    T: NewService,
    F: FnMut(In, &mut T::Service) -> Out + Clone,
    Out: IntoFuture,
    Out::Error: From<T::Error>,
    U: IntoNewService<T>, 

Create factory for apply service.