How do I show a specific page/BLTNItem on demand?

**Problem Description:**
How do I show a specific page/BLTNItem on demand?

**Steps to reproduce:**
Say I have a selection of 5 bulletins (created like in the documentation), and on press of a button I only want to show bulletin number 4

Currently I'm using:
`bulletinManager.showBulletin(above: self, animated: true)
`
`let fourthItem: BLTNItem = makeFourthPage()
`
`bulletinManager.push(item: fourthItem)
`

**However**, I get a "glitch" during the showBulletin animation where it very briefly shows the root item for half a second before pushing the intended Item.

I've tried changing the order, so creating and pushing the item first, then "showBulletin" but I get this error:

> You must call the `prepare` function before interacting with the bulletin.

**Environment:**
- Device: iPhone XR
- OS: 12.1
- Version of BulletinBoard: latest