Coroutine emits (ObservableEmitter.onNext) values with
send, completes (ObservableEmitter.onComplete) when the coroutine completes or channel is explicitly closed and emits error (ObservableEmitter.onError) if coroutine throws an exception or closes channel with a cause. Unsubscribing cancels running coroutine.
send are suspended appropriately when subscribers apply back-pressure and to ensure that
onNext is not invoked concurrently.
Coroutine context can be specified with context argument. If the context does not have any dispatcher nor any other ContinuationInterceptor, then Dispatchers.Default is used. Method throws IllegalArgumentException if provided context contains a Job instance.
Note: This is an experimental api. Behaviour of publishers that work as children in a parent scope with respect