title: DataFormatterStyle has no member .mediumStyle
body: <p>In closure I want to set styles for date and time,</p>
  
  <pre><code>private let dateFormatter: DateFormatter = {
      let formatter = DateFormatter()
      formatter.dateStyle = .mediumStyle
      formatter.timeStyle = .shortStyle
      return formatter
  }()
  </code></pre>
  
  <p>but getting such error</p>
  
  <pre><code>Type 'DataFormatterStyle has no member .mediumStyle'
  </code></pre>
  
  <p>Previously with NSDateFormatter worked fine</p>