let coreDataStack = CoreDataStack(name: "Database")
coreDataStack.start()

enum MigrationVersion: CoreDataMigrationVersion {
    case version1
    case version2
    case version3
    
    static var current: Self {
        guard let current = allCases.last else {
            fatalError("no model versions found")
        }

        return current
    }
    
    var nextVersion: Self? {
        switch self {
        case .version1:
            return .version2
        case .version2:
            return .version3
        case .version3:
            return nil
        }
    }
    
    var identifier: Int? {
        switch self {
        case .version1: return 1
        case .version2: return 2
        case .version3: return 3
        }
    }
}

class Migrator: CoreDataMigratorProtocol {
    typealias T = MigrationVersion
}

let coreDataStack = CoreDataStack(name: "Database", migrator: Migrator())
if coreDataStack.isStarted {
    // Nothing or callback
} else {
    coreDataStack.subscribe(completion: {
        // Nothing or callback. stack was started
    })
        
    coreDataStack.start()
}

    }
    try? context.saveToStore()  

        try? context.saveToStore()
    }

        try? context.saveToStore()
    }