anchor.diff:    /**
      * Looks up the value of a name in the scope of the closure. The
      * result is a mirror on that value.
  +   *
  +   * Let *s* be the contents of the string used to construct the symbol [name].
  +   *
  +   * If the expression *s* occurs within the source code of the reflectee,
  +   * and that any such occurrence refers to a declaration outside the reflectee,
  +   * then let *v* be the result of evaluating the expression *s* at such
  +   * an occurrence.
  +   * If *s = this*, and the reflectee was defined within the instance scope of
  +   * an object *o*, then let *v* be *o*.
  +   *
  +   * The returned value is the result of invoking the method [reflect] on
  +   * *v*.
      */
     Future<InstanceMirror> findInContext(Symbol name);
   }
  
positive.code: 
    /**
     * Perform [invocation] on [reflectee].
     *
     * If [reflectee] doesn't support the invocation, its [noSuchMethod]
     * method will be called with either [invocation] or another
     * equivalent instance of [Invocation].
     */
    delegate(Invocation invocation);
  }
  
negative.code: abstract class InstanceMirror implements ObjectMirror {
    /**
     * A mirror on the type of the reflectee.
     *
     * Returns a mirror on the actual class of the reflectee.
     * The class of the reflectee may differ from
     * the object returned by invoking [runtimeType] on
     * the reflectee.
     */
    ClassMirror get type;
  
  