//! [`Slot`]: one running subscription's identity and pending future.
usesuper::SubscriptionGen;usecrate::application::BoxFuture;/// One active subscription: its stable `id`, the generator that produces
/// its futures, and the in-flight future awaiting its next message.
pubstructSlot<M>{pub(crate)id:u64,
pub(crate)spawn:Option<SubscriptionGen<M>>,
pub(crate)pending:Option<BoxFuture<M>>,
}