anchor.diff:      }
     }
   
  +  /// Whether to deselect a selected item on click or keyboard enter.
  +  bool get deselectOnActivate => isMultiSelect;
  +
  +  @protected
  +  void onListItemSelected(suggestion) {
  +    if (isSingleSelect) {
  +      showPopup = false;
  +    }
  +    if (!selection.isSelected(suggestion)) {
  +      selection.select(suggestion);
  +    } else if (deselectOnActivate) {
  +      selection.deselect(suggestion);
  +    }
  +  }
  +
     @override
     void handleUpKey(html.KeyboardEvent event) {
       if (showPopup) {
  
positive.code:     }
    }
  
    void onListItemSelected(suggestion) {
      if (isSingleSelect) {
        showPopup = false;
      }
      if (selection.isSelected(suggestion)) {
        selection.deselect(suggestion);
      } else {
        selection.select(suggestion);
      }
    }
  
    @override
    ngOnInit() {
      _isInitialized = true;
  
negative.code: 
  import 'package:angular/angular.dart';
  import 'package:angular_forms/angular_forms.dart';
  import 'package:meta/meta.dart';
  import 'package:angular_components/button_decorator/button_decorator.dart';
  import 'package:angular_components/content/deferred_content.dart';
  import 'package:angular_components/dynamic_component/dynamic_component.dart';
  