How to enable cancellation correctly?

[Rossil2012]

When should I call "Promise.config({ cancellation: true })"?

1. Anytime when I import bluebird:

   import { Promise } from "bluebird";
   Promise.config({ cancellation: true });

2. Anytime when I create a Promise:

   import { Promise } from "bluebird";
   ...
   Promise.config({ cancellation: true });
   promA = new Promise(...);
   ...
   Promise.config({ cancellation: true });
   promB = new Promise(...);

3. On the entrypoint:

   // index.ts
   import { Promise } from "bluebird";
   Promise.config({ cancellation: true });