anchor.diff:    return false;
   }
   
  -/**
  - * Walks up the class hierarchy to find a method declaration with the given
  - * [name].
  - *
  - * Note that it's not possible to tell if there's an implementation via
  - * noSuchMethod().
  - */
  +/// Walks up the class hierarchy to find a method declaration with the given
  +/// [name].
  +///
  +/// Note that it's not possible to tell if there's an implementation via
  +/// noSuchMethod().
   DeclarationMirror getDeclaration(ClassMirror classMirror, Symbol name) {
     if (classMirror.declarations.containsKey(name)) {
       return classMirror.declarations[name];
  
positive.code: 
  import 'dart:mirrors';
  
  /**
   * Returns the qualified name of [t].
   */
  Symbol getTypeName(Type t) => reflectClass(t).qualifiedName;
  
  /**
   * Returns true if [o] implements [type].
   */
  bool implements(Object o, Type type) =>
      classImplements(reflect(o).type, reflectClass(type));
  
  /**
   * Returns true if the class represented by [classMirror] implements the class
   * represented by [interfaceMirror].
   */
  bool classImplements(ClassMirror classMirror, ClassMirror interfaceMirror) {
    if (classMirror == null) return false;
    // TODO: change to comparing mirrors when dartbug.com/19781 is fixed
  
negative.code:   return null;
  }
  
  /// Closurzes a method reflectively.
  class Method /* implements Function */ {
    final InstanceMirror mirror;
    final Symbol symbol;
  