 public typealias PlaygroundQuickLook = QuickLookObject
 
 extension PlaygroundQuickLook {
-  /// Initialize for the given `instance`.
-  ///
-  /// If the dynamic type of `instance` conforms to
+  /// Initialize for the given `subject`.
+  ///
+  /// If the dynamic type of `subject` conforms to
   /// `CustomPlaygroundQuickLookable`, returns the result of calling
   /// its `customPlaygroundQuickLook` method.  Otherwise, returns
-  /// a `PlaygroundQuickLook` synthesized for `instance` by the
+  /// a `PlaygroundQuickLook` synthesized for `subject` by the
   /// language.  Note: in some cases the result may be
-  /// `.Text(String(reflecting: instance))`.
-  ///
-  /// Note: If the dynamic type of `instance` has value semantics,
-  /// subsequent mutations of `instance` will not observable in
+  /// `.Text(String(reflecting: subject))`.
+  ///
+  /// Note: If the dynamic type of `subject` has value semantics,
+  /// subsequent mutations of `subject` will not observable in
   /// `Mirror`.  In general, though, the observability of such
   /// mutations is unspecified.
-  public init(reflecting instance: Any) {
-    if let customized? = instance as? CustomPlaygroundQuickLookable {
+  public init(reflecting subject: Any) {
+    if let customized? = subject as? CustomPlaygroundQuickLookable {
       self = customized.customPlaygroundQuickLook()
     }
     else {
-      if let q? = Swift.reflect(instance).quickLookObject {
+      if let q? = Swift.reflect(subject).quickLookObject {
         self = q
       }
       else {
-        self = .Text(String(reflecting: instance))
+        self = .Text(String(reflecting: subject))
       }
     }
   }

  }
  
  /// A collection of `Child` elements describing the structure of the
  /// reflected instance.
  public let children: Children

  /// Suggests a display style for the reflected instance.
  public let displayStyle: DisplayStyle?
}


    func customMirror() -> Mirror { return mirror }
  }
  
  /// Return a specific descendant of the reflected subject, or `nil`
  /// if no such descendant exists.
  ///
  /// A `String` argument selects the first `Child` with a matching label.
