anchor.diff:      UNIVERSE
     ];
   
  -  /**
  -   * The name of this element kind.
  -   */
  +  /// The name of this element kind.
     final String name;
   
  -  /**
  -   * The ordinal value of the element kind.
  -   */
  +  /// The ordinal value of the element kind.
     final int ordinal;
   
  -  /**
  -   * The name displayed in the UI for this kind of element.
  -   */
  +  /// The name displayed in the UI for this kind of element.
     final String displayName;
   
  -  /**
  -   * Initialize a newly created element kind to have the given [displayName].
  -   */
  +  /// Initialize a newly created element kind to have the given [displayName].
     const ElementKind(this.name, this.ordinal, this.displayName);
   
     @override
  
positive.code:   }
  }
  
  /**
   * The location of an element within the element model.
   *
   * Clients may not extend, implement or mix-in this class.
   */
  abstract class ElementLocation {
    /**
     * Return the path to the element whose location is represented by this
     * object. Clients must not modify the returned array.
     */
    List<String> get components;
  
    /**
     * Return an encoded representation of this location that can be used to
     * create a location that is equal to this location.
     */
    String get encoding;
  }
  
  /**
   * An object that can be used to visit an element structure.
   *
   * Clients may not extend, implement or mix-in this class. There are classes
   * that implement this interface that provide useful default behaviors in
   * `package:analyzer/dart/ast/visitor.dart`. A couple of the most useful include
   * * SimpleElementVisitor which implements every visit method by doing nothing,
   * * RecursiveElementVisitor which will cause every node in a structure to be
   *   visited, and
   * * ThrowingElementVisitor which implements every visit method by throwing an
   *   exception.
   */
  abstract class ElementVisitor<R> {
    R visitClassElement(ClassElement element);
  
  
negative.code:   @override
    String toString() => name;
  
    /// Return the kind of the given [element], or [ERROR] if the element is
    /// `null`. This is a utility method that can reduce the need for null checks
    /// in other places.
    static ElementKind of(Element element) {
      if (element == null) {
        return ERROR;
  