How to setup a unit test for atlaskit package UserPicker using react testing library & JEST?

I am using a atlaskit component UserPicker in my JIRA Custom UI application.
I need to setup a unit test for it. But I cannot find a way to ‘expect’ the component on the screen(I have tried using ByRole, ById and ByLabel but it didn’t work).
It would be really helpful if someone can me guide me on how to setup a unit test atlaskit components like UserPicker.