cellular-automata/lib/service/engine_service.dart

import 'package:rules_of_living/src/Engine.dart';

class EngineService {
  Engine _uncachedEngineAccess;

  Engine get engine => _uncachedEngineAccess ?? _setCachedAndReturn(Engine());
  void set engine(Engine newEngine) {
    _uncachedEngineAccess = newEngine;
  }

  Engine _setCachedAndReturn(Engine newEngine) {
    engine = newEngine;
    return newEngine;
  }
}