- Marked Response as nullable in UIKit categories.

- Changed UIButton category to behave like the UIKit category
- Improved UIButton category documentation

UIKit+AFNetworking/UIButton+AFNetworking.h

@@ -52,7 +52,7 @@ NS_ASSUME_NONNULL_BEGIN
 
  @param imageCache The image cache.
  */
-+ (void)setSharedImageCache:(id <AFImageCache>)imageCache;
++ (void)setSharedImageCache:(__nullable id <AFImageCache>)imageCache;
 
 ///------------------------------------
 /// @name Accessing Response Serializer
@@ -103,13 +103,13 @@ NS_ASSUME_NONNULL_BEGIN
  @param state The control state.
  @param urlRequest The URL request used for the image request.
  @param placeholderImage The image to be set initially, until the image request finishes. If `nil`, the button will not change its image until the image request finishes.
- @param success A block to be executed when the image request operation finishes successfully. This block has no return value and takes two arguments: the server response and the image. If the image was returned from cache, the request and response parameters will be `nil`.
+ @param success A block to be executed when the image request operation finishes successfully. This block has no return value and takes two arguments: the server response and the image. If the image was returned from cache, the response parameter will be `nil`.
  @param failure A block object to be executed when the image request operation finishes unsuccessfully, or that finishes successfully. This block has no return value and takes a single argument: the error that occurred.
  */
 - (void)setImageForState:(UIControlState)state
           withURLRequest:(NSURLRequest *)urlRequest
         placeholderImage:(nullable UIImage *)placeholderImage
-                 success:(nullable void (^)(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image))success
+                 success:(nullable void (^)(NSURLRequest *request, NSHTTPURLResponse * __nullable response, UIImage *image))success
                  failure:(nullable void (^)(NSError *error))failure;
 
 
@@ -151,11 +151,13 @@ NS_ASSUME_NONNULL_BEGIN
  @param state The control state.
  @param urlRequest The URL request used for the image request.
  @param placeholderImage The background image to be set initially, until the background image request finishes. If `nil`, the button will not change its background image until the background image request finishes.
+ @param success A block to be executed when the image request operation finishes successfully. This block has no return value and takes two arguments: the server response and the image. If the image was returned from cache, the response parameter will be `nil`.
+ @param failure A block object to be executed when the image request operation finishes unsuccessfully, or that finishes successfully. This block has no return value and takes a single argument: the error that occurred.
  */
 - (void)setBackgroundImageForState:(UIControlState)state
                     withURLRequest:(NSURLRequest *)urlRequest
                   placeholderImage:(nullable UIImage *)placeholderImage
-                           success:(nullable void (^)(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image))success
+                           success:(nullable void (^)(NSURLRequest *request, NSHTTPURLResponse * __nullable response, UIImage *image))success
                            failure:(nullable void (^)(NSError *error))failure;
 
 

UIKit+AFNetworking/UIButton+AFNetworking.m

@@ -121,7 +121,7 @@ static const char * af_backgroundImageRequestOperationKeyForState(UIControlState
 #pragma clang diagnostic pop
 }
 
-+ (void)setSharedImageCache:(id <AFImageCache>)imageCache {
++ (void)setSharedImageCache:(__nullable id <AFImageCache>)imageCache {
     objc_setAssociatedObject(self, @selector(sharedImageCache), imageCache, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
 }
 
@@ -165,7 +165,7 @@ static const char * af_backgroundImageRequestOperationKeyForState(UIControlState
 - (void)setImageForState:(UIControlState)state
           withURLRequest:(NSURLRequest *)urlRequest
         placeholderImage:(UIImage *)placeholderImage
-                 success:(void (^)(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image))success
+                 success:(void (^)(NSURLRequest *request, NSHTTPURLResponse * __nullable response, UIImage *image))success
                  failure:(void (^)(NSError *error))failure
 {
     [self cancelImageRequestOperationForState:state];
@@ -173,7 +173,7 @@ static const char * af_backgroundImageRequestOperationKeyForState(UIControlState
     UIImage *cachedImage = [[[self class] sharedImageCache] cachedImageForRequest:urlRequest];
     if (cachedImage) {
         if (success) {
-            success(nil, nil, cachedImage);
+            success(urlRequest, nil, cachedImage);
         } else {
             [self setImage:cachedImage forState:state];
         }
@@ -231,7 +231,7 @@ static const char * af_backgroundImageRequestOperationKeyForState(UIControlState
 - (void)setBackgroundImageForState:(UIControlState)state
                     withURLRequest:(NSURLRequest *)urlRequest
                   placeholderImage:(UIImage *)placeholderImage
-                           success:(void (^)(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image))success
+                           success:(void (^)(NSURLRequest *request, NSHTTPURLResponse * __nullable response, UIImage *image))success
                            failure:(void (^)(NSError *error))failure
 {
     [self cancelBackgroundImageRequestOperationForState:state];
@@ -239,7 +239,7 @@ static const char * af_backgroundImageRequestOperationKeyForState(UIControlState
     UIImage *cachedImage = [[[self class] sharedImageCache] cachedImageForRequest:urlRequest];
     if (cachedImage) {
         if (success) {
-            success(nil, nil, cachedImage);
+            success(urlRequest, nil, cachedImage);
         } else {
             [self setBackgroundImage:cachedImage forState:state];
         }

UIKit+AFNetworking/UIImageView+AFNetworking.h

@@ -50,7 +50,7 @@ NS_ASSUME_NONNULL_BEGIN
 
  @param imageCache The image cache.
  */
-+ (void)setSharedImageCache:(id <AFImageCache>)imageCache;
++ (void)setSharedImageCache:(__nullable id <AFImageCache>)imageCache;
 
 ///------------------------------------
 /// @name Accessing Response Serializer
@@ -105,8 +105,8 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (void)setImageWithURLRequest:(NSURLRequest *)urlRequest
               placeholderImage:(nullable UIImage *)placeholderImage
-                       success:(nullable void (^)(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image))success
-                       failure:(nullable void (^)(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error))failure;
+                       success:(nullable void (^)(NSURLRequest *request, NSHTTPURLResponse * __nullable response, UIImage *image))success
+                       failure:(nullable void (^)(NSURLRequest *request, NSHTTPURLResponse * __nullable response, NSError *error))failure;
 
 /**
  Cancels any executing image operation for the receiver, if one exists.

UIKit+AFNetworking/UIImageView+AFNetworking.m

@@ -81,7 +81,7 @@
 #pragma clang diagnostic pop
 }
 
-+ (void)setSharedImageCache:(id <AFImageCache>)imageCache {
++ (void)setSharedImageCache:(__nullable id <AFImageCache>)imageCache {
     objc_setAssociatedObject(self, @selector(sharedImageCache), imageCache, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
 }
 
@@ -121,8 +121,8 @@
 
 - (void)setImageWithURLRequest:(NSURLRequest *)urlRequest
               placeholderImage:(UIImage *)placeholderImage
-                       success:(void (^)(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image))success
-                       failure:(void (^)(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error))failure
+                       success:(void (^)(NSURLRequest *request, NSHTTPURLResponse * __nullable response, UIImage *image))success
+                       failure:(void (^)(NSURLRequest *request, NSHTTPURLResponse * __nullable response, NSError *error))failure
 {
     [self cancelImageRequestOperation];