     self.reachability = reachability
   }
 
-  deinit {
-    SCNetworkReachabilitySetCallback(reachability, nil, nil)
-    SCNetworkReachabilitySetDispatchQueue(reachability, nil)
-    callback = nil
+  deinit() {
+    os_log("** deinit", log: .default, type: .debug)
   }
 
   public func reach() -> OlaStatus {

  /// - Parameter callback: The callback to apply when reachability changes.
  /// - Returns: `true` if the callback has been successfully installed.
  func install(callback: @escaping (OlaStatus) -> Void) -> Bool
  
}

// MARK: Internals

}

final public class Ola: Reaching {

  private let reachability: SCNetworkReachability!

  /// Create a new `Ola` object for `host`.
