code: function bidirectionalBlurBinding (event) {
          var bind = this._bindingListeners.value;
          var newValue = this._transform(bind.transform, event.target.getValue(), "fromWidget");
  
          this._hasFocus = false;
  
          if (this._hasPlaceholder) {
              // We're handling the placeholder. Set an empty string in the datamodel instead of the placeholder value
              // Note that the placeholder is set by the type function, so we know the field must be empty
              ariaUtilsJson.setValue(bind.inside, bind.to, "", bind.cb);
          } else {
              ariaUtilsJson.setValue(bind.inside, bind.to, newValue, bind.cb);
          }
          this._firstFocus = true;
  
      }
docs: Being a BindableWidget we already have one direction binding of value (from the datamodel to the widget). This
  function is the callback for implementing the other bind, from the widget to the datamodel. The value is set in
  the datamodel on blur. It also takes care of calling the 'on blur' callback if it was defined.
  @param {aria.DomEvent} event blur event
  @private