How do I save?

Sorry, I'm having lots of trouble trying to use xCode/Swift.
I'm looking at Interface Builder and trying to save a view class to a different name.
I type in the name, hit enter or put the cursor somewhere else or in any way leave the Class field.
The class name changes back to what it was before I typed the new class name.
It's infuriating.

I have a pic but can't figure out how to post it here.
How can I make it save my class name?

OK I figured it out. I had it selected and apparently, you can't do that!