I am trying to manually convert some code from Objective-C to Swift, but I only know how to use Swift. 

```
ADBannerView *adView = [[ADBannerView alloc] initWithFrame:CGRectMake(0, self.view.frame.size.height - 50, 320, 50)];
[self.view addSubview:adView];

```

I was able to convert the line starting with `ADBannerView *adView =` except for everything inside the `CGRectMake()`. I did not understand the second line starting with `[self.view`.

Please help. Thanks!