Multiline UIButton and autolayout

Question

I have created a view controller that looks like this:

I want the two

Answer 1

add the missing constraints:

if let label = button.titleLabel {

    button.addConstraint(NSLayoutConstraint(item: label, attribute: .top, relatedBy: .equal, toItem: button, attribute: .top, multiplier: 1.0, constant: 0.0))
    button.addConstraint(NSLayoutConstraint(item: label, attribute: .bottom, relatedBy: .equal, toItem: button, attribute: .bottom, multiplier: 1.0, constant: 0.0))
}