title: Extension UIScrollView in one target. Use extended methods in UITableView instance will crash in another target
body: <p>In Cocoa Touch Framework Target. I add following methods to UIScrollView.</p>
  
  <pre><code>public extension UIScrollView {
  
    public func beginRefresh() {
      print("beginRefresh")
    }
  
    public func endRefresh() {
      print("endRefresh")
    }
  
  }
  </code></pre>
  
  <p>In iOS App Target as Demo App. I invoke those methods on UITableView instance. It crash.</p>
  
  <pre><code>override func viewDidLoad() {
      super.viewDidLoad()
  
      tableView.beginRefresh()
  }
  </code></pre>
  
  <p>Crash Log:</p>
  
  <blockquote>
    <p>2016-08-10 16:22:29.736 DTRefresh iOS Example[7373:210619]
    -[UITableView beginRefresh]: unrecognized selector sent to instance 0x7fc91b019e00 2016-08-10 16:22:29.751 DTRefresh iOS
    Example[7373:210619] <strong>* Terminating app due to uncaught exception
    'NSInvalidArgumentException', reason: '-[UITableView beginRefresh]:
    unrecognized selector sent to instance 0x7fc91b019e00'
    *</strong> First throw call stack: (     0   CoreFoundation                      0x0000000109c39d85 <strong>exceptionPreprocess + 165  1   libobjc.A.dylib<br>
    0x000000010b9dddeb objc_exception_throw + 48  2   CoreFoundation<br>
    0x0000000109c42d3d -[NSObject(NSObject) doesNotRecognizeSelector:] +
    205   3   CoreFoundation                      0x0000000109b88cfa
    ___forwarding_</strong> + 970    4   CoreFoundation                      0x0000000109b888a8 _CF_forwarding_prep_0 + 120  5   DTRefresh iOS
    Example               0x0000000109a54a81
    _TFC21DTRefresh_iOS_Example18ListViewController11viewDidLoadfT_T_ + 561   6   DTRefresh iOS Example               0x0000000109a54b22
    _TToFC21DTRefresh_iOS_Example18ListViewController11viewDidLoadfT_T_ + 34  7   UIKit                               0x000000010a5fc984
    -[UIViewController loadViewIfRequired] + 1198     8   UIKit                               0x000000010a5fccd3 -[UIViewController view] + 27    9   UIKit<br>
    0x000000010a4d2fb4 -[UIWindow addRootViewControllerViewIfPossible] +
    61    10  UIKit                               0x000000010a4d369d
    -[UIWindow _setHidden:forced:] + 282  11  UIKit                               0x00000001193a5d16 -[UIWindowAccessibility
    _orderFrontWithoutMakingKey] + 68     12  UIKit                               0x000000010a4e5180 -[UIWindow makeKeyAndVisible] + 42   13  UIKit<br>
    0x000000010a459ed9 -[UIApplication
    _callInitializationDelegatesForMainScene:transitionContext:] + 4131   14  UIKit                               0x000000010a460568
    -[UIApplication _runWithMainScene:transitionContext:completion:] + 1769   15  UIKit                               0x000000010a45d714
    -[UIApplication workspaceDidEndTransaction:] + 188    16  FrontBoardServices                  0x000000010d86e8c8
    <strong>FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK</strong> + 24     17  FrontBoardServices                  0x000000010d86e741
    -[FBSSerialQueue _performNext] + 178  18  FrontBoardServices                  0x000000010d86eaca -[FBSSerialQueue _performNextFromRunLoopSource] +
    45    19  CoreFoundation                      0x0000000109b5f301
    <strong>CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION</strong> + 17   20  CoreFoundation                      0x0000000109b5522c
    __CFRunLoopDoSources0 + 556   21  CoreFoundation                      0x0000000109b546e3 __CFRunLoopRun + 867     22  CoreFoundation<br>
    0x0000000109b540f8 CFRunLoopRunSpecific + 488     23  UIKit<br>
    0x000000010a45cf21 -[UIApplication _run] + 402    24  UIKit<br>
    0x000000010a461f09 UIApplicationMain + 171    25  DTRefresh iOS Example 
    0x0000000109a54662 main + 114     26  libdyld.dylib<br>
    0x000000010c4a192d start + 1  27  ???<br>
    0x0000000000000001 0x0 + 1 ) libc++abi.dylib: terminating with
    uncaught exception of type NSException</p>
  </blockquote>