如何使用SWIFT正确地向包含UILabel的UITextField添加约束？

// 创建UITextField和UILabel
let textField = UITextField()
let label = UILabel()

// 将UILabel添加为UITextField的子视图
textField.addSubview(label)

// 设置translatesAutoresizingMaskIntoConstraints为false
textField.translatesAutoresizingMaskIntoConstraints = false

// 添加UITextField的约束
textField.widthAnchor.constraint(equalToConstant: 200).isActive = true
textField.heightAnchor.constraint(equalToConstant: 40).isActive = true
textField.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20).isActive = true
textField.topAnchor.constraint(equalTo: view.topAnchor, constant: 20).isActive = true

// 添加UILabel的约束
label.widthAnchor.constraint(equalToConstant: 100).isActive = true
label.heightAnchor.constraint(equalToConstant: 20).isActive = true
label.leadingAnchor.constraint(equalTo: textField.leadingAnchor, constant: 10).isActive = true
label.topAnchor.constraint(equalTo: textField.topAnchor, constant: 10).isActive = true

// 设置UILabel的contentHuggingPriority和contentCompressionResistancePriority
label.setContentHuggingPriority(.required, for: .horizontal)
label.setContentCompressionResistancePriority(.required, for: .horizontal)