we only want to display the toaster if `(this.lastUpdatesAvailable - this.updatesQueue.length > 0)`.
To make things clear and readable, I'd use a boolean variable named `mustDisplayToaster` to hold the result of this comparison. You can use whatever name sounds better to you :)

Of  course, you need to check this before changing `this.lastUpdatesAvailable` :) so maybe you can change `this.lastUpdatesAvailable` after changing the toaster's class.