code: function ($scope, key) {
                          $parse(key).assign($scope, void 0);
                          this.forget(key);
  
                          var watchId = key + $scope.$id;
  
                          if (this._watchers[watchId]) {
                              // execute the de-registration function
                              this._watchers[watchId]();
                              delete this._watchers[watchId];
                          }
  
                          return this;
                      }
docs: Unbind a storage key from a $scope property
  
  @public
  
  @param  {Object}  $scope  The angular $scope object
  @param  {String}  key     The key to remove from bindings
  
  @return {Locker}