Function actix_service::apply_cfg

pub fn apply_cfg<F, C, T, R, S, E>(
    srv: T, 
    f: F
) -> ApplyConfigService<F, C, T, R, S, E> where
    F: FnMut(C, &mut T) -> R,
    T: Service,
    R: Future<Output = Result<S, E>>,
    S: Service, 

Convert Fn(&Config, &mut Service) -> Future<Service> fn to a NewService