nil is the only return value permitted in initializer? : <p>I'm attempting to subclass UICollectionViewFlowLayout but I get the error that 'nil is the only return value permitted in an initializer.' I attempted to check the super class for an initializer and if there wasn't, I would return nil, but alas, I get another error saying that self is immutable.</p>

<pre><code>import UIKit

class CollectionViewSpringLayout: UICollectionViewFlowLayout {
    var dynamicAnimator: UIDynamicAnimator?
    override init() {


        self.minimumInteritemSpacing = 10
        self.minimumInteritemSpacing = 10
        //self.itemSize = CGSizeMake(44, 44)
        self.sectionInset = UIEdgeInsetsMake(10, 10, 10, 10)
        self.dynamicAnimator = UIDynamicAnimator(collectionViewLayout: self)
        return self
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}
</code></pre>
