Function observe

observe(bus: BaseBus, pattern: string): Observable<BusObservation>
Observe bus events matching a pattern. Returns an Observable of { cmd, result }. Each subscribe creates an independent listener.
Parameters
- bus: BaseBus
- pattern: string
Returns Observable<BusObservation>
Example
```
const obs = observe(bus, 'cartAdd');
const sub = obs.subscribe(({ cmd, result }) => {
  if (result.ok) console.log('added', cmd.target);
});
// later
sub.unsubscribe();
```
- Defined in observable.ts:78