title: Trying to get frame.height of one of the 2 views, that filled equally inside of a stackview
body: <p>I have 2 views inside a vertical stackview(bothalf and tophalf). Their constraints dependent on that stackview.I have a horizontal stackview(containerStackView3) inside the botHalfView. Its constraints leading,trailing and height dependent on botHalfView. In debugging window i can see also on console, height of the bothalfview.frame.height=0 which i added as a constraint  for horizontalstackview. Therefore horizontalstackview inside the bothalfview not showing any dimension. To which constraint i should assign the horizontalstackview's height? Or any other solution to this?</p>
  
  <pre><code>       let containerStackView3 = UIStackView()
          containerStackView3.translatesAutoresizingMaskIntoConstraints = false
          containerStackView3.axis = .vertical
          containerStackView3.distribution = .fillEqually
          containerStackView3.spacing = 1
   //adding views
          containerStackView1.addArrangedSubview(botHalfView2)
          botHalfView2.addSubview(containerStackView3)
  
  //constraints bothalfview 
          botHalfView2.bottomAnchor.constraint(equalTo: 
          containerStackView1.bottomAnchor, constant: 0).isActive = true
          botHalfView2.leadingAnchor.constraint(equalTo: 
          containerStackView1.leadingAnchor, constant: 0).isActive = true
          botHalfView2.trailingAnchor.constraint(equalTo: 
          containerStackView1.trailingAnchor, constant: 0).isActive = true
  
  // Constraints of the stack view inside the bothalfview
          containerStackView3.leadingAnchor.constraint(equalTo: 
          botHalfView2.leadingAnchor, constant: 0).isActive = true
          containerStackView3.trailingAnchor.constraint(equalTo: 
          botHalfView2.trailingAnchor, constant: 0).isActive = true
          containerStackView3.bottomAnchor.constraint(equalTo: 
          botHalfView2.bottomAnchor, constant: 0).isActive = true
  
    containerStackView3.heightAnchor.constraint(equalToConstant:botHalfView2.frame.height).isActive = true
  </code></pre>