         }
     }
 
-    class KeychainStore: NSObject {
+    class KeychainStore {
         private let keychain: Keychain
         private let key = "slack-api-token"
 
-        override init() {
+        init() {
             let bundle = NSBundle.mainBundle()
             let appPrefix = bundle.objectForInfoDictionaryKey("AppIdentifierPrefix")
             let bundleIdentifier = bundle.bundleIdentifier

        return NSNotificationCenter.defaultCenter()
    }

    class FileStore: NSObject {
        func save(config: SlackApiConfig) {
            if let rootUrl = documentRootUrl() {
                ensureRootUrl(rootUrl)

import Foundation
import KeychainAccess

class SlackApiConfigService {
    static let instance = SlackApiConfigService()
    class func sharedService() -> SlackApiConfigService {
        return instance
    }

    private init() {
    }

    func save(config: SlackApiConfig) {
