How to use the @bentley/ui-ninezone.Direction.Left function in @bentley/ui-ninezone

const verticalToolbar =
      
            
            
            
          
        }
      />;

    return (
      
    );
  }
}

class FrontstageNavigationWidget extends React.Component {

  private _horizontalToolbar =
    
          
          
        
      }
    />;

  private _verticalToolbar =
    
          
          
        
      }
    />;

  public render() {
    return (
      
    );

constructor(props: NavigationWidgetProps) {
    super(props);

    this.widgetType = WidgetType.Navigation;
    this.verticalDirection = (props.verticalDirection !== undefined) ? props.verticalDirection : Direction.Left;
    this.horizontalPanelAlignment = ToolbarPanelAlignment.End;
    this._navigationAidId = (props.navigationAidId !== undefined) ? props.navigationAidId : "";

    const activeStageName = FrontstageManager.activeFrontstageDef ? FrontstageManager.activeFrontstageDef.id : "";
    this.widgetBaseName = `[${activeStageName}]NavigationWidget`;
  }