fun <P, T> Store<P?>.map(lens: Lens<P & Any, T>): Store<T>

on a Store of nullable data this creates a Store with a nullable parent and non-nullable value. It can be called using a Lens on a non-nullable parent (that can be created by using the @Lenses-annotation), but you have to ensure, that the resulting Store is never used, when it's parent's value is null. Otherwise, a NullPointerException is thrown.



Lens to use to create the Store