title: fontSize is always 17 when load from storyboard
body: <p>I'm trying to write an <code>UIFont</code> extension to increase fontSize when the word display in 5.5 inch iPhone. Hear is my code :</p>
  
  <pre><code>public override class func initialize() {
          struct Static {
              static var token: dispatch_once_t = 0
          }
  
          dispatch_once(&amp;Static.token) {
              let originalSelector = Selector("systemFontOfSize:")
              let swizzledSelector = Selector("systemFontOfFlexibleSize:")
  
              let originalMethod = class_getClassMethod(self, originalSelector)
              let swizzledMethod = class_getClassMethod(self, swizzledSelector)
              method_exchangeImplementations(originalMethod, swizzledMethod);
          }
  
      }
  
      class func systemFontOfFlexibleSize(fontSize: CGFloat)-&gt;UIFont {
          print(fontSize)
          if UIScreen.mainScreen().bounds.height &gt;= 736.0 {
              return self.systemFontOfFlexibleSize(fontSize + 2)
          } else {
              return self.systemFontOfFlexibleSize(fontSize)
          }
      }
  </code></pre>
  
  <p>This worked well when I use the method <code>systemFontOfSize</code> in code. When I use xib or storyboard create a label, <code>systemFontOfFlexibleSize</code> still called, but the fontSize is always 17 no matter what I set in storyboard.
  Could someone explain this or any other elegant solution?</p>
  
  <p>I appreciate your help, thanks in advance.</p>