I have a stack view with 2 buttons.

[![enter image description here](https://i.stack.imgur.com/d14AY.png)](https://i.stack.imgur.com/d14AY.png) 

When ButtonA is hidden, buttonB is stretched.

[![enter image description here](https://i.stack.imgur.com/WMe2Y.png)](https://i.stack.imgur.com/WMe2Y.png)

I would like Button B to have the same width as it was specified. How do I set the UIStuckView appropriately.
Here is the setup I am doing right now:
 [![enter image description here](https://i.stack.imgur.com/RgZU2.png)](https://i.stack.imgur.com/RgZU2.png)