How common is the of(undefined) pattern in angular, and what are its benefits?

I recenlty was reviewing a project where Angular observables are heavily utilized across both components and services, as to "reactive programming approach". I've noticed the use of of(undefined) in many observable chains.

While I understand that of(undefined) serves as an initial trigger in observable streams, I'm curious about how widespread this approach is among developers and whether it’s considered a best practice for specific scenarios.

Here's an example to illustrate how this is used:

private doAction(): Observable<void> {
return of(undefined).pipe(
switchMap(() => {
// perform actions
return of(undefined);
}),
catchError((err) => {
console.error('Error occurred:', err);
return of(undefined); // Handle error by returning another undefined observable
}),
finalize(() => {
// cleanup code here
})
);
}

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