Makes `Producer` internal.

RxCocoa/Common/Observables/Implementations/KVOObservable.swift

@@ -11,8 +11,11 @@ import Foundation
 import RxSwift
 #endif
 
-class KVOObservable<Element> : _Producer<Element?>
-                             , KVOObservableProtocol {
+class KVOObservable<Element>
+    : ObservableType
+    , KVOObservableProtocol {
+    typealias E = Element?
+
     unowned var target: AnyObject
     var strongTarget: AnyObject?
     
@@ -30,7 +33,7 @@ class KVOObservable<Element> : _Producer<Element?>
         }
     }
     
-    override func run<O : ObserverType where O.E == Element?>(observer: O, cancel: Disposable, setSink: (Disposable) -> Void) -> Disposable {
+    func subscribe<O : ObserverType where O.E == Element?>(observer: O) -> Disposable {
         let observer = KVOObserver(parent: self) { (value) in
             if value as? NSNull != nil {
                 observer.on(.Next(nil))

RxCocoa/Common/Observables/NSObject+Rx.swift

@@ -59,7 +59,7 @@ extension NSObject {
     - returns: Observable sequence of objects on `keyPath`.
     */
     public func rx_observe<Element>(keyPath: String, options: NSKeyValueObservingOptions = [.New, .Initial], retainSelf: Bool = true) -> Observable<Element?> {
-        return KVOObservable(object: self, keyPath: keyPath, options: options, retainTarget: retainSelf)
+        return KVOObservable(object: self, keyPath: keyPath, options: options, retainTarget: retainSelf).asObservable()
     }
 
 }

RxSwift/Observables/Implementations/Producer.swift

@@ -8,18 +8,12 @@
 
 import Foundation
 
-public class _Producer<Element> : Producer<Element> {
-    public override init() {
-        super.init()
-    }
-}
-
-public class Producer<Element> : Observable<Element> {
+class Producer<Element> : Observable<Element> {
     override init() {
         super.init()
     }
     
-    public override func subscribe<O : ObserverType where O.E == Element>(observer: O) -> Disposable {
+    override func subscribe<O : ObserverType where O.E == Element>(observer: O) -> Disposable {
         let sink = SingleAssignmentDisposable()
         let subscription = SingleAssignmentDisposable()
         
@@ -43,7 +37,7 @@ public class Producer<Element> : Observable<Element> {
         return d
     }
     
-    public func run<O : ObserverType where O.E == Element>(observer: O, cancel: Disposable, setSink: (Disposable) -> Void) -> Disposable {
+    func run<O : ObserverType where O.E == Element>(observer: O, cancel: Disposable, setSink: (Disposable) -> Void) -> Disposable {
         abstractMethod()
     }
 }