title: Swift method not visible in objective C
body: <p>I have project using Swift 3.2 and Objective-C compiling with Xcode Version 9.0 (9A235).  It compiles fine in Swift 3.2.  However, when I switch to Swift 4.0, the methods declared in Swift is no longer visible in Objective-C.  The error is <code>No visible @interface "UserAPI" declares the selector ...</code> </p>
  
  <p><a href="https://i.stack.imgur.com/c7QZz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/c7QZz.png" alt="enter image description here"></a><a href="https://i.stack.imgur.com/mwJKT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/mwJKT.png" alt="enter image description here"></a></p>