inv = [NSInvocation invocationWithMethodSignature:[self methodSignatureForSelector:@selector(updateFrame)]];
    NSLog(@"COUNT %u", [inv retainCount]);
    [inv setTarget:self];
    [inv setSelector:@selector(updateFrame)];
    displayLink_ = [[CADisplayLink displayLinkWithTarget:inv selector:@selector(invoke)] retain];
    NSLog(@"COUNT %u", [inv retainCount]);