Force private cache-control requests to be public (cachable) with AFHTTPSessionManager

cache.m

  [sessionManager
      setDataTaskWillCacheResponseBlock:^NSCachedURLResponse *
                                        (NSURLSession *session,
                                         NSURLSessionDataTask *dataTask,
                                         NSCachedURLResponse *
                                             proposedResponse) {
        NSURLResponse *response = proposedResponse.response;
        NSHTTPURLResponse *HTTPResponse = (NSHTTPURLResponse *)response;
        NSDictionary *headers = HTTPResponse.allHeaderFields;

        NSCachedURLResponse *cachedResponse;
        if (headers[@"Cache-Control"]) {
          NSMutableDictionary *modifiedHeaders = headers.mutableCopy;
          modifiedHeaders[@"Cache-Control"] = [modifiedHeaders[@"Cache-Control"]
              stringByReplacingOccurrencesOfString:@"private"
                                        withString:@"public"];
          NSHTTPURLResponse *modifiedResponse =
              [[NSHTTPURLResponse alloc] initWithURL:HTTPResponse.URL
                                          statusCode:HTTPResponse.statusCode
                                         HTTPVersion:@"HTTP/1.1"
                                        headerFields:modifiedHeaders];

          cachedResponse = [[NSCachedURLResponse alloc]
              initWithResponse:modifiedResponse
                          data:proposedResponse.data
                      userInfo:proposedResponse.userInfo
                 storagePolicy:proposedResponse.storagePolicy];

        } else {
          cachedResponse = proposedResponse;
        }
        return cachedResponse;
      }];

  return sessionManager;