anchor.diff:      }
     }
   
  -  /**
  -   * Append a textual representation of this element to the given [buffer].
  -   */
  +  /// Append a textual representation of this element to the given [buffer].
     void appendTo(StringBuffer buffer) {
       if (_name == null) {
         buffer.write("<unnamed ");
  
positive.code:   @override
    String toString() => encoding;
  
    /**
     * Decode the [encoding] of a location into a list of components and return
     * the components.
     */
    List<String> _decode(String encoding) {
      List<String> components = new List<String>();
      StringBuffer buffer = new StringBuffer();
  
negative.code:   }
  }
  
  /// A base class for concrete implementations of an [ExecutableElement].
  abstract class ExecutableElementImpl extends ElementImpl
      with TypeParameterizedElementMixin
      implements ExecutableElement {
    /// The unlinked representation of the executable in the summary.
    final UnlinkedExecutable serializedExecutable;
  
    /// A list containing all of the parameters defined by this executable
    /// element.
    List<ParameterElement> _parameters;
  
    /// The declared return type of this executable element.
    DartType _declaredReturnType;
  
    /// The inferred return type of this executable element.
    DartType _returnType;
  
    /// The type of function defined by this executable element.
    FunctionType _type;
  
    /// Initialize a newly created executable element to have the given [name] and
    /// [offset].
    ExecutableElementImpl(String name, int offset)
        : serializedExecutable = null,
          super(name, offset);
  
    /// Initialize a newly created executable element to have the given [name].
    ExecutableElementImpl.forNode(Identifier name)
        : serializedExecutable = null,
          super.forNode(name);
  
    /// Initialize using the given serialized information.
    ExecutableElementImpl.forSerialized(
        this.serializedExecutable, ElementImpl enclosingElement)
        : super.forSerialized(enclosingElement);
  
    /// Set whether this executable element's body is asynchronous.
    void set asynchronous(bool isAsynchronous) {
      _assertNotResynthesized(serializedExecutable);
      setModifier(Modifier.ASYNCHRONOUS, isAsynchronous);
  