private _getListData(listName: string): Promise<ISPLists> {

const queryString: string = '$select=Title,ID,Created,Author/ID,Author/Title&$expand=Author/ID,Author/Title&$Orderby=SortOrder';

return this.context.spHttpClient
  .get(`${this.context.pageContext.web.absoluteUrl}/_api/web/lists/GetByTitle('${listName}')/items`,//?${queryString}`,
  SPHttpClient.configurations.v1)
  .then((response: SPHttpClientResponse) => {
    if (response.status === 404) {
      Log.error('js-display-List', new Error('List not found.'));
      return [];
    }else {
      return response.json();
    }
  });
 }