code: private static Map<State, StateStrategy> createStrategyMap() {
          final Map<State, StateStrategy> map = new EnumMap<>(State.class);
          map.put(State.CLOSED, new StateStrategyClosed());
          map.put(State.OPEN, new StateStrategyOpen());
          return map;
      }
docs: Creates the map with strategy objects. It allows access for a strategy for a given
  state.
  
  @return the strategy map