How can I update the privacy parameter in FBSDKGraphRequest when starting a live video?

Question

I am trying to update the privacy parameter so that the live video my app starts is posted on the user's timeline with the privacy set to "ALL_FRIENDS". I have looked through the documentation and the code I have come up with does not work:

NSString* livePath =  [@"/" stringByAppendingPathComponent:[token.userID stringByAppendingPathComponent:@"live_videos"]];
FBSDKProfile *profile = [FBSDKProfile currentProfile];

if(profile.userID){
    livePath = [@"/" stringByAppendingPathComponent:[profile.userID stringByAppendingPathComponent:@"live_videos"]];
}

NSMutableDictionary* param = @{
                               }.mutableCopy;
[param setObject:@"Test Title" forKey:@"title"];
[param setObject:@"Test Description" forKey:@"description"];
[param setObject:@"privacy" forKey:@"{@\"value\": \"ALL_FRIENDS\"}"];
[[[FBSDKGraphRequest alloc] initWithGraphPath:livePath
                                   parameters:param
                                  tokenString:token.tokenString
                                      version:@"v2.6"
                                   HTTPMethod:@"POST"]
 startWithCompletionHandler:^(FBSDKGraphRequestConnection *connection, id result, NSError *error) { //More code here }

Answer 1

I figured it out using Facebook's graph explorer (https://developers.facebook.com/tools/explorer/?method=POST&path=118477909176601%2Flive_videos&version=v3.2&privacy=%7B%27value%27%20%3A%20%27ALL_FRIENDS%27%7D&classic=0). The code for setting the param to update the privacy settings is below.

[[[FBSDKGraphRequest alloc] initWithGraphPath:livePath
                                   parameters:@{ @"privacy": @"{'value' : 'ALL_FRIENDS'}",}
                                  tokenString:token.tokenString
                                      version:@"v2.6"
                                   HTTPMethod:@"POST"]
 startWithCompletionHandler:^(FBSDKGraphRequestConnection *connection, id result, NSError *error) {