title: More than two items optional on AutoLayout
body: <p>I have four label items (subtotal, tax, tips and promotion) which is designed as follows.</p>
  
  <p>Each item is connected to each other. In other words, each label is used top space constraint. </p>
  
  <p><code>Promotion</code> and <code>Tip</code> are optional. If user wants to add, then he can. Therefore, I also added constraints for each of these label items' <code>Height == 0</code> at the initial state. If any of them is added, then I change the <code>Height</code> to <code>25</code> to make it visible. </p>
  
  <p>However, you can see if there is no <code>tip</code>, then <code>promotion</code> position is weird.
  I expected to see promotion just under the tax rather than seeing extra white spaces.</p>
  
  <p>I wonder how developers usually handle this issue?</p>
  
  <p><strong>Before adding Tips</strong>
  <a href="https://i.stack.imgur.com/Exy0F.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Exy0F.png" alt="enter image description here"></a></p>
  
  <p><strong>After adding Tips</strong></p>
  
  <p><a href="https://i.stack.imgur.com/dPzKJ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/dPzKJ.png" alt="enter image description here"></a></p>