Singleton with properties in Swift 3 : <p>In Apple's <a href="https://developer.apple.com/library/prerelease/content/documentation/Swift/Conceptual/BuildingCocoaApps/AdoptingCocoaDesignPatterns.html#//apple_ref/doc/uid/TP40014216-CH7-ID6">Using Swift with Cocoa and Objective-C document</a> (updated for Swift 3) they give the following example of the Singleton pattern:</p>

<pre><code>class Singleton {
    static let sharedInstance: Singleton = {
        let instance = Singleton()

        // setup code

        return instance
    }()
}
</code></pre>

<p>Let's imagine that this singleton needs to manage a variable array of Strings. How/where would I declare that property and ensure it gets initialized properly to an empty <code>[String]</code> array?</p>
