StateMapper<State extends Built<State, StateBuilder> , StateBuilder extends Builder<State, StateBuilder> , Substate> typedef
StateMapper<State extends Built<State, StateBuilder> , StateBuilder extends Builder<State, StateBuilder> , Substate> =
Substate Function(State state)
StateMapper takes a state model and maps it to the values one cares about
Implementation
typedef StateMapper<State extends Built<State, StateBuilder>,
StateBuilder extends Builder<State, StateBuilder>, Substate>
= Substate Function(State state);