Understanding Fragment's setRetainInstance(boolean)

Question

Starting with the documentation:

public void setRetainInstance (boolean retain)

Control whether a fragment instance is retained across Activity re

Answer 1

setRetainInstance(boolean) is useful when you want to have some component which is not tied to Activity lifecycle. This technique is used for example by rxloader to "handle Android's activity lifecyle for rxjava's Observable" (which I've found here).