goodbye ObjectiveC

Sources/Progress+ObjectiveC.swift

@@ -28,16 +28,12 @@ import Foundation
 
 // MARK: - Progress
 
+@available(*, unavailable, message: "CoreStore Objective-C is now obsoleted in preparation for Swift concurrency.")
 extension Progress {
-    
-    /**
-     Sets a closure that the `NSProgress` calls whenever its `fractionCompleted` changes. You can use this instead of setting up KVO.
-     
-     - parameter closure: the closure to execute on progress change
-     */
+
     @objc
     dynamic public func cs_setProgressHandler(_ closure: ((_ progress: Progress) -> Void)?) {
-        
-        self.setProgressHandler(closure)
+
+        fatalError()
     }
 }