AWSCognito iOS Swift Share Identity between app and extension

cogniostore.swift

// Framework
import Foundation
import AWSCognito     //pod
import KeychainAccess //pod

public struct Apple {
    public struct KeyChain {
        public static let Group = "YOUR GROUP NAME"
        public static let Service = "YOUR SERVICE NAME"
    }
}
public struct Amazon {
    public struct Cognito {
        public static let PoolId = "YOUR POOL ID"
        public static let Region = AWSRegionType
    }
}
public class MyCognito {
    
    public var identityId:String? = ""
    var credentialsProvider: AWSCognitoCredentialsProvider
    let cognito: AWSCognito
    let keychain = Keychain(service: Apple.KeyChain.Service, accessGroup: Apple.KeyChain.Group)
    init() {
        credentialsProvider = AWSCognitoCredentialsProvider(
               regionType: Amazon.Cognito.Region,  
               identityPoolId: Amazon.Cognito.PoolId)
        if let kid = try? keychain.getString("CognitoIdentityId") {
            credentialsProvider = AWSCognitoCredentialsProvider(
                   regionType: Amazon.Cognito.Region, 
                   identityId: kid,
                   identityPoolId: Amazon.Cognito.PoolId, 
                   logins: nil)
            identityId = kid
        }
        let configuration = AWSServiceConfiguration(
                                            region: Amazon.Cognito.Region, 
                                            credentialsProvider: credentialsProvider)
        AWSServiceManager.defaultServiceManager().defaultServiceConfiguration = configuration
        cognito = AWSCognito.defaultCognito()
    }
    
    func requestIdentity() {
        credentialsProvider.getIdentityId().continueWithBlock() { (task) -> AnyObject! in
            if let error = task.error {
                print("Could not request identity: \(error.userInfo)")
            } else {
                self.identityId = self.credentialsProvider.identityId
                if let error = try? keychain.set(self.credentialsProvider.identityId, key: "CognitoIdentityId")      {
                    print("error: \(error)")
                }
            }
            return nil
        }
    }
}

class ViewController {
  let mycognito = MyCognito()

    override func viewDidLoad() {
        mycognito.requestIdentity()
  }
}

class TodayViewController {
  let mycognito = MyCognito()

    override func viewDidLoad() {
        mycognito.requestIdentity()
  }
}