         let callback: SCNetworkReachabilityCallBack = { (reachability, flags, info) in
             guard let info = info else { return }
 
-            // `weakifiedReachability` is guaranteed to exist by virtue of our retain
-            // release callbacks which we provided to the `SCNetworkReachabilityContext`.
+            // `weakifiedReachability` is guaranteed to exist by virtue of our
+            // retain/release callbacks which we provided to the `SCNetworkReachabilityContext`.
             let weakifiedReachability = Unmanaged<ReachabilityWeakifier>.fromOpaque(info).takeUnretainedValue()
 
             // The weak `reachability` _may_ no longer exist if the `Reachability`

}

/**
 The `ReachabilityWeakifier` class weakly wraps the `Reachability` class
 in order to break retain cycles when interacting with CoreFoundation
 APIs.

 CoreFoundation callbacks expect a pair or retain/release whenever providing
 an info parameter. These callbacks exist to guard against memory management
 race conditions when invoking the callbacks.

 #### Race Condition



 If we pass `Reachability` to CoreFoundtion while also providing retain/
 release callbacks, we would create a retain cycle once CoreFoundation
 retains our `Reachability` class. This fixes the crashes and his how
 CoreFoundation expects the API to be used, but doesn't play nicely with
 Swift/ARC. This cycle would only be broken after manually calling
 `stopNotifier()` — `deinit` would never be called.

 #### ReachabilityWeakifier

