//init views
    let foo = UILabel()
    foo.text = "Hello"
    foo.textAlignment = .center

    let bar = UILabel()
    bar.text = "World"
    bar.textAlignment = .center

    let button = UIButton()
    button.setTitle("GO", for: .normal)

    let buttonContainer = UIView()
    buttonContainer.backgroundColor = .darkGray

    let content = UIStackView()
    content.distribution = .fillEqually

  view.addSubview(content)
  content.addArrangedSubview(foo)
  content.addArrangedSubview(bar)

  view.addSubview(buttonContainer)
  buttonContainer.addSubview(button)

  foo.translatesAutoresizingMaskIntoConstraints = false
  bar.translatesAutoresizingMaskIntoConstraints = false
  button.translatesAutoresizingMaskIntoConstraints = false
  buttonContainer.translatesAutoresizingMaskIntoConstraints = false
  content.translatesAutoresizingMaskIntoConstraints = false
  
  let constraints: [NSLayoutConstraint] = [
      content.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 50),
      content.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor),
      content.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor),
      buttonContainer.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20),
      buttonContainer.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -20),
      buttonContainer.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -20),
      button.centerXAnchor.constraint(equalTo: buttonContainer.centerXAnchor),
      button.bottomAnchor.constraint(equalTo: buttonContainer.bottomAnchor, constant: -32),
      button.topAnchor.constraint(equalTo: buttonContainer.topAnchor, constant: 32)
  ]

  NSLayoutConstraint.activate(constraints)

    //add subviews and arragned subviews, deactivates autorresizing mask
    view.add {
        content.arrange {
            foo
            bar
        }
        buttonContainer.add {
            button
        }
    }

    //collects constraints and activates them
    layout {
        content.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 50)
        content.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor)
        content.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor)
        buttonContainer.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20)
        buttonContainer.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -20)
        buttonContainer.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -20)
        button.centerXAnchor.constraint(equalTo: buttonContainer.centerXAnchor)
        button.bottomAnchor.constraint(equalTo: buttonContainer.bottomAnchor, constant: -32)
        button.topAnchor.constraint(equalTo: buttonContainer.topAnchor, constant: 32)
    }