use of unresolved identifier 'LocationManager()'

let oauth = OAuth2ClientCredentials(settings: [
    "client_id": "X4KP6ZK0ST-jF46KpAhxzg",
    "client_secret": "m7TVywafskUun0OR0GeNbb9nP5sAUzbFGf8xVNv0bw9L4KPKg0O4lKiyYEETanI9",
    "authorize_uri": "https://api.yelp.com/oauth2/token",
    "secret_in_body": true,
    "keychain": false
])

let locationManager = LocationManager()

var isAuthorizedForLocation: Bool
var isAuthenticatedWithToken: Bool

lazy var locationPermissionButton:  UIButton = {
    let title = self.isAuthorizedForLocation ? "Location Permissions Granted" : "Request Location Permissions"
    let button = UIButton(type: .system)
    let controlState = self.isAuthorizedForLocation ? UIControlState.disabled : UIControlState.normal
    button.isEnabled = !self.isAuthorizedForLocation
    button.setTitle(title, for: controlState)
    button.addTarget(self, action: #selector(PermissionsController.requestLocationPermissions), for: .touchUpInside)


    button.translatesAutoresizingMaskIntoConstraints = false
    button.backgroundColor = UIColor(colorLiteralRed: 62/255.0, green: 71/255.0, blue: 79/255.0, alpha: 1.0)
    button.setTitleColor(UIColor(colorLiteralRed: 178/255.0, green: 187/255.0, blue: 185/255.0, alpha: 1.0), for: .disabled)
    button.setTitleColor(.white, for: .normal)
    button.layer.cornerRadius = 5
    button.clipsToBounds = true

    return button
}()

lazy var oauthTokenButton:  UIButton = {
    let title = self.isAuthenticatedWithToken ? "OAuth Token Granted" : "Request OAuth Token"
    let button = UIButton(type: .system)
    let controlState = self.isAuthenticatedWithToken ? UIControlState.disabled : UIControlState.normal
    button.isEnabled = !self.isAuthenticatedWithToken
    button.setTitle(title, for: controlState)
    button.addTarget(self, action: #selector(PermissionsController.requestOAuthToken), for: .touchUpInside)

    button.translatesAutoresizingMaskIntoConstraints = false
    button.backgroundColor = UIColor(colorLiteralRed: 62/255.0, green: 71/255.0, blue: 79/255.0, alpha: 1.0)
    button.setTitleColor(UIColor(colorLiteralRed: 178/255.0, green: 187/255.0, blue: 185/255.0, alpha: 1.0), for: .disabled)
    button.setTitleColor(.white, for: .normal)
    button.layer.cornerRadius = 5
    button.clipsToBounds = true

    return button
}()

lazy var dismissButton: UIButton = {
    let button = UIButton(type: .system)
    button.setTitle("Dismiss", for: .normal)
    button.tintColor = .white
    button.addTarget(self, action: #selector(PermissionsController.dismissPermissions), for: .touchUpInside)

    button.translatesAutoresizingMaskIntoConstraints = false
    return button
}()

required init?(coder aDecoder: NSCoder) {
    fatalError("init coder not implemented")
}

init(isAuthorizedForLocation authorized: Bool, isAuthenticatedWithToken authenticated: Bool) {
    self.isAuthorizedForLocation = authorized
    self.isAuthenticatedWithToken = authenticated
    super.init(nibName: nil, bundle: nil)
}

override func viewDidLoad() {
    super.viewDidLoad()

    view.backgroundColor = UIColor(colorLiteralRed: 95/255.0, green: 207/255.0, blue: 128/255.0, alpha: 1.0)
}


override func viewWillLayoutSubviews() {
    super.viewWillLayoutSubviews()

    let stackView = UIStackView(arrangedSubviews: [locationPermissionButton, oauthTokenButton])
    stackView.alignment = .center
    stackView.axis = .vertical
    stackView.distribution = .equalSpacing
    stackView.spacing = 16.0
    stackView.translatesAutoresizingMaskIntoConstraints = false

    view.addSubview(stackView)
    view.addSubview(dismissButton)

    NSLayoutConstraint.activate([
        locationPermissionButton.heightAnchor.constraint(equalToConstant: 64.0),
        locationPermissionButton.leadingAnchor.constraint(equalTo: stackView.leadingAnchor),
        locationPermissionButton.trailingAnchor.constraint(equalTo: stackView.trailingAnchor),
        oauthTokenButton.heightAnchor.constraint(equalToConstant: 64.0),
        oauthTokenButton.leadingAnchor.constraint(equalTo: stackView.leadingAnchor),
        oauthTokenButton.trailingAnchor.constraint(equalTo: stackView.trailingAnchor),
        stackView.centerYAnchor.constraint(equalTo: view.centerYAnchor),
        stackView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 32.0),
        stackView.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -32.0),
        dismissButton.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -16),
        dismissButton.centerXAnchor.constraint(equalTo: view.centerXAnchor)
    ])

}

func requestLocationPermissions() {
    do {
        try locationManager.requestLocationAuthorization()
    } catch LocationError.disallowedByUser {
        // Show alert to user
    } catch let error {
        print("Location Authorization Error \(error.localizedDescription)")
    }
}

func requestOAuthToken() {
    oauth.authorize { authParams, error in
        if let params = authParams {
            guard let token = params["access_token"] as? String, let expiration
                = params["expires_in"] as? TimeInterval else { return }

            let account = YelpAccount(accessToken: token, expiration:
                expiration, grantDate: Date())

            do {
                try? account.save()
                self.oauthTokenButton.setTitle("OAuth Token Granted", for: .disabled)
                self.oauthTokenButton.isEnabled = false
            }
        } else {
            print ("Authorization was cancelled or went wong")
        }
    }
}

func dismissPermissions() {
    dismiss(animated: true, completion: nil)
}