Duplicate NSUserActivity Displaying in Spotlight

Hello,

I have the following simple code running in the ViewDidLoad for a simple ViewController:

    self.userActivity = [[NSUserActivity alloc]
                        initWithActivityType:@"com.company.activity-type"];


    self.userActivity.title = self.restaurant.name;
    self.userActivity.keywords = [NSSet setWithArray:@[@"LOOK",@"HERE"]];


    NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:@"suge knight", @"killed 2pac", nil];
    self.userActivity.userInfo = dict;

    CSSearchableItemAttributeSet *attributeSet = [[CSSearchableItemAttributeSet alloc] initWithItemContentType:(NSString *)kUTTypeImage];
    attributeSet.title = @"big hitz";
    attributeSet.contentDescription = [NSString stringWithFormat:@"%@\n%@",@"cali",@"rollin'"];
    attributeSet.thumbnailData = [NSData dataWithData:UIImagePNGRepresentation(self.restaurant.imageForSpotlight)];
    attributeSet.identifier = @"asdf";

    self.userActivity.contentAttributeSet = attributeSet;
    self.userActivity.requiredUserInfoKeys = [NSSet setWithArray:self.userActivity.userInfo.allKeys];
    self.userActivity.eligibleForSearch = YES;
    self.userActivity.eligibleForPublicIndexing = YES;

The following code works great and displays the NSUserActivity in spotlight 100% fine. The problem is that if I visit this ViewController multiple times, duplicates of the same NSUserActivity spotlight results come up in spotlight. What can I do to prevent this? I only want one instance of the activity displaying in spotlight.

Thanks for reading.