'already scheduled' event always fires for unique every job

[mrosendin]

hello,

Following the unique every example, I've noticed that the 'already scheduled' event always fires. I don't understand the need for this event, can you please explain?

console output on app start:

[nodemon] starting `node ./bin/www`
Processing job with id 2 at 2019-12-05T23:37:37.730Z
Job completed with data  { deliveredAt: '2019-12-05T23:37:37.731Z' }
job already scheduled: 2

Processing job with id 2 at 2019-12-05T23:37:39.896Z

Processing job with id 2 at 2019-12-05T23:37:42.067Z
job already scheduled: 2

Processing job with id 2 at 2019-12-05T23:37:44.232Z
job already scheduled: 2

...