         threeWaySwizzle(#selector(NSObject.keyPathsForValuesAffectingValue(forKey:)), with: #selector(NSObject.__old_unswizzled_keyPathsForValuesAffectingValue(forKey:)))
         threeWaySwizzle(#selector(NSObject.automaticallyNotifiesObservers(forKey:)), with: #selector(NSObject.__old_unswizzled_automaticallyNotifiesObservers(forKey:)))
         
-        return [:]
+        return nil
     }()
     
     /// Performs a 3-way swizzle between `NSObject` and `__KVOKeyPathBridgeMachinery`.

        let rootMethod = class_getClassMethod(rootClass, selector)!
        method_exchangeImplementations(rootMethod, unswizzledMethod)
    }
    
    @nonobjc static var keyPathTableLock = NSLock()
    
    @nonobjc fileprivate static func _bridgeKeyPath(_ keyPath: __owned AnyKeyPath) -> String {
        guard let keyPathString = keyPath._kvcKeyPathString else { fatalError("Could not extract a String from KeyPath \(keyPath)") }
        __KVOKeyPathBridgeMachinery.keyPathTableLock.lock()
        defer { __KVOKeyPathBridgeMachinery.keyPathTableLock.unlock() }
        __KVOKeyPathBridgeMachinery.keyPathTable[keyPathString] = keyPath
        return keyPathString
    }
    
    @nonobjc fileprivate static func _bridgeKeyPath(_ keyPath:String?) -> AnyKeyPath? {
        guard let keyPath = keyPath else { return nil }
        __KVOKeyPathBridgeMachinery.keyPathTableLock.lock()
        defer { __KVOKeyPathBridgeMachinery.keyPathTableLock.unlock() }
        let path = __KVOKeyPathBridgeMachinery.keyPathTable[keyPath]
        return path
    }
    
    @objc override class func automaticallyNotifiesObservers(forKey key: String) -> Bool {

// must coexist, so it was renamed. The old name must not be used in the
// new runtime.
@objc private class __KVOKeyPathBridgeMachinery : NSObject {
    @nonobjc static var swizzler: ()? = {
        /*
         Move all our methods into place. We want the following:
         __KVOKeyPathBridgeMachinery's automaticallyNotifiesObserversForKey:, and keyPathsForValuesAffectingValueForKey: methods replaces NSObject's versions of them
