How to use Auto Layout to center a view vertically in its superview?

Question

Objective-C

In general, the essence of the question is as follows:
There is a View (hereinafter the first), it contains another View (hereinafter the second). The dimensions of the second view are fixed (for example, a square), and the height of the first view is unknown (depends on the size of the content).
The task is as follows: how, using constraints, to make sure that the second view does not change its coordinates along the X axis, and the coordinate along the Y axis changes depending on the height value of the first view, i.e. so that the second view is centered vertically?
I hope I explained clearly.

Answer 1

As I understand it, you need something like this:
Image
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