title: how to set 'setter' of an computed property to private?
body: <p>I know how to set 'setter' of an stored property to private (e.g. <code>public private(set) var name: String = "John"</code>) but how do we set 'setter' of an computed property to private? In this case the 'setter' for the variable '<code>age</code>'. When I tried to put an keyword private in front of <code>set(newAge){}</code>, XCode display an error. So is it possible to set 'setter' of an computed property to private?</p>
  
  <pre><code>public class Person {
  
      public private(set) var name: String = "John"
  
      var age: Int{
          get {
              return 10
          }
          set(newAge){ // how to set this setter to private so to restrict modification
  
          }
      }
  }
  </code></pre>