pub trait AmbientRuntime: Future + Sealded {
// Provided methods
fn block_on(self) -> Self::Output
where Self: Sized { ... }
async fn with_timeout(self, t: Duration) -> Option<Self::Output>
where Self: Sized { ... }
fn spawn(self) -> JoinHandle<Self::Output>
where Self: Sized + Send + 'static,
Self::Output: Send + 'static { ... }
}