Add functionality for adding custom strategy for restoring some specific fields.
It can be very useful when:
You wanna add nontrivial logic for new and old value. (e.g. while view was in recreating process some changes happened in presenter, and you do not want lose them)
With Kotlin lateinit fields (e.g. instance state has been saved before lateinit var has been initialised and then you don't want set null in lateinit var after restoring state)
Add functionality for adding custom strategy for restoring some specific fields. It can be very useful when: