Cesium memory management

Hi there.
How does the cesium memory works ?

1. When entity leaving the canvas does it keeps the render or it gets removes and the context / ref is saved ?
2. Does there any cache that is collecting all the data of entities and etc.?

I’m rendering over 100 entities and each one of the running screen space event and running functions .
3. Doe’s Screen Space Event has a cache or memory storage ?