//
//  User.swift
//  SpotifySessionManager
//
//  Created by Julian Grosshauser on 11/03/15.
//  Copyright (c) 2015 Julian Grosshauser. All rights reserved.
//

class User {

    //MARK: Properties

    static let sessionUpdatedNotification: String = "SessionUpdatedNotification"
    static let sessionRemovedNotification: String = "SessionRemovedNotification"

    static let sharedInstance: User = User()

    var session: SPTSession? = nil {
        didSet {
            let notificationCenter = NSNotificationCenter.defaultCenter()

            if let newSession = session {
                notificationCenter.postNotificationName(User.sessionUpdatedNotification, object: nil)
            } else {
                notificationCenter.postNotificationName(User.sessionRemovedNotification, object: nil)
            }
        }
    }
}

//
//  User.swift
//  SpotifySessionManager
//
//  Created by Julian Grosshauser on 11/03/15.
//  Copyright (c) 2015 Julian Grosshauser. All rights reserved.
//

class User {

    //MARK: Properties

    static let sessionUpdatedNotification: String = "SessionUpdatedNotification"
    static let sessionRemovedNotification: String = "SessionRemovedNotification"

    static let sharedInstance: User = User(session: nil)

    var session: SPTSession? {
        didSet {
            let notificationCenter = NSNotificationCenter.defaultCenter()

            if let newSession = session {
                notificationCenter.postNotificationName(User.sessionUpdatedNotification, object: nil)
            } else {
                notificationCenter.postNotificationName(User.sessionRemovedNotification, object: nil)
            }
        }
    }

    //MARK: Initialization

    init(session: SPTSession?) {
        self.session = session
    }
}

--- 
+++ 
@@ -13,9 +13,9 @@
     static let sessionUpdatedNotification: String = "SessionUpdatedNotification"
     static let sessionRemovedNotification: String = "SessionRemovedNotification"
 
-    static let sharedInstance: User = User(session: nil)
+    static let sharedInstance: User = User()
 
-    var session: SPTSession? {
+    var session: SPTSession? = nil {
         didSet {
             let notificationCenter = NSNotificationCenter.defaultCenter()
 
@@ -26,10 +26,4 @@
             }
         }
     }
-
-    //MARK: Initialization
-
-    init(session: SPTSession?) {
-        self.session = session
-    }
 }
Set default value of property `session` to `nil`

This makes a custom `init` method unnecessary.
