How do you insert a UIView into a UILabel? 

**Goal:**

Make a separate UIView the background of an existing UI component. 

**Example**

```
    //Views
    let viewOne = UIImageView(); //bottom view, e.g. a UIImageView
    let viewTwo = UILabel();     //top view, e.g. a UILabel

    //Traditional
    self.addSubview(viewOne);
    self.addSubview(viewTwo);   //viewTwo goes on top 

    //Target
    viewTwo.addSubview(viewOne);
    self.addSubview(viewTwo;    //goal is to encapsulate viewOne into viewTwo

```

**Question**

How do you insert viewOne into the bottom of viewTwo? Do you use a layer of viewOne, I can't seem to get this successful!