anchor.diff:          _typeParameters = element.typeParameters,
           _variables = element.fields.where(_isNotSynthetic).toList();
   
  -  /**
  -   * Creates an [ElementWalker] which walks the child elements of a compilation
  -   * unit element.
  -   */
  +  /// Creates an [ElementWalker] which walks the child elements of a compilation
  +  /// unit element.
     ElementWalker.forCompilationUnit(CompilationUnitElement compilationUnit)
         : element = compilationUnit,
           _accessors = compilationUnit.accessors.where(_isNotSynthetic).toList(),
  
positive.code:   List<VariableElement> _variables;
    int _variableIndex = 0;
  
    /**
     * Creates an [ElementWalker] which walks the child elements of a class
     * element.
     */
    ElementWalker.forClass(ClassElement element)
        : element = element,
          _accessors = element.accessors.where(_isNotSynthetic).toList(),
  
negative.code: import 'package:analyzer/src/dart/element/type.dart';
  import 'package:analyzer/src/generated/resolver.dart';
  
  /// A visitor that resolves declarations in an AST structure to already built
  /// elements.
  ///
  /// The resulting AST must have everything resolved that would have been
  /// resolved by a [CompilationUnitBuilder] (that is, must be a valid
  /// [RESOLVED_UNIT1]). This class must not assume that the
  /// [CompilationUnitElement] passed to it is any more complete than a
  /// [COMPILATION_UNIT_ELEMENT].
  class DeclarationResolver extends RecursiveAstVisitor<Object> {
    /// The compilation unit containing the AST nodes being visited.
    CompilationUnitElementImpl _enclosingUnit;
  
    /// The type provider used to access the known types.
    TypeProvider _typeProvider;
  
    /// The [ElementWalker] we are using to keep track of progress through the
    /// element model.
    ElementWalker _walker;
  
    DeclarationResolver();
  
    /// Resolve the declarations within the given compilation [unit] to the
    /// elements rooted at the given [element]. Throw an
    /// [ElementMismatchException] if the element model and compilation unit do
    /// not match each other.
    void resolve(CompilationUnit unit, CompilationUnitElement element) {
      _enclosingUnit = element;
      _typeProvider = _enclosingUnit.context?.typeProvider;
  