How to turn on feature in Xcode Editor

What is that feature called that shows a picture of the entire contents of the file on the right-hand side of the editor and shows it very small like it's zoomed out and shows the part of the file that is currently showing in the editor in a different shade in the picture? I am describing this to the best of my ability. I hope it comes across clearly.

This is called the "Minimap".

The menu for this in on an icon at the top-right of Xcode... (the middle of the three lower buttons, in the screenshot.)

How to turn on feature in Xcode Editor
 
 
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