pub trait Scheduler: Clone + Send + 'static {
fn run_topology(
&self,
topology: &mut Topology,
main_channel: &Sender<AsyncMessage>
) -> Slab<Option<Sender<AsyncMessage>>>;
fn spawn<T: Send + 'static>(
&self,
future: impl Future<Output = T> + Send + 'static
) -> Task<T>;
fn spawn_blocking<T: Send + 'static>(
&self,
future: impl Future<Output = T> + Send + 'static
) -> Task<T>;
}