chrome extensions how to handle multiple notifications at the same time

[Antonio Cota]

If a notification A is created and subsequentally another notification, say B, is created, with notification A not previously closed, what should happen?

By the tests I made I didn't get any clear behavior. Some times the new notification B replaced the first one A, other times the notification A was still showing, with the notification B not showed at all.

In addition what should be the right behavior if the two notifications belongs to two different extensions?

Should I implement any check in my code?