RxJS, advice with lettable operators

Question

I'm getting lost with the new lettable operators.

I succeeded trying to use mergeMap :

import { mergeMap } from 'rxjs/operators';

But I don't know how to import operators such as finally :

import { ? } from 'rxjs/?';

Where is this operator ? Is there a rule to find each of the ones you need ?

Answer 1

Since finally is a JavaScript keyword and thus can't be used as a function name, the operator has been renamed finalize (as indicated by the documentation on lettable pipeable operators.