anchor.diff:  final _uidCounter = new _UidCounter();
   
   /**
  + * Binds an expression to the value of a radio element or option,
  + * to be used when that element is selected.
  + *
  + * When the element is selected, the `ng-model` property of that element is set to the bound value.
  + * Note that `expr` can be any type; i.e., it is not restricted to [String].
  + *
    * Usage:
    *
    *     <input type=radio ng-model=model [ng-value=expr]>
  
positive.code:  *
   * When present, the value of this `ng-value` one-way attribute is assigned to
   * the `ng-model` property when the corresponding radio element or option is
   * selected. Note that `expr` can be not any type; i.e., it is not restricted
   * to [String].
   */
  @Decorator(selector: 'input[type=radio][ng-model][ng-value]')
  @Decorator(selector: 'option[ng-value]')
  
negative.code: }
  
  /**
   * Assigns the value of a bound expression to the model when an input checkbox is
   * checked.
   *
   * Usage:
   *
   *     <input type=checkbox
   *            ng-model=model
   *            [ng-true-value=expr]>
   *
   * Note that the expression can be of any type, not just [String].
   * Also see [InputCheckboxDirective], [NgFalseValue].
   */
  @Decorator(selector: 'input[type=checkbox][ng-model][ng-true-value]')
  class NgTrueValue {
  