gistfile1.txt

    NSMutableSet *aSet = [[NSMutableSet alloc] init];
    
    // add NSDictionary objects to aSet
    NSDictionary *aDictionary = @{@(1) : @"1"};
    [aSet addObject:aDictionary];
    
    // Now test for membership
    
    if ([aSet containsObject:aDictionary]) {
        NSLog(@"set contains  object");
    }
    else {
        NSLog(@"set does NOT contain object");
    }
    
    NSMutableSet *newSet = [NSMutableSet setWithSet:aSet];
    if ([newSet containsObject:aDictionary]) {
        NSLog(@"newSet contains object");
    }
    else {
        NSLog(@"newSet does NOT contain object");
    }