Get operation using SP Http Client

GetSPDataHttpClient.ts

try {
      let spHttpClient : SPHttpClient = context.spHttpClient;
      let url = `${context.pageContext.web.absoluteUrl}/_api/web/lists/GetByTitle('${listTitle}')/Items?$select=Author/EMail,*&$expand=Author&$filter=Author/EMail eq 'XYZ@xyz.com'`;
      spHttpClient.get(url, SPHttpClient.configurations.v1).then((response : SPHttpClientResponse) => {
          if(response.ok)
          {
              response.json().then((responseJson : any) => {
              console.log(responseJson);
              if (this.isValidObject(responseJson) && responseJson.value.length !== 0) {
                resolve({
                  associatedItem: responseJson.value[0]
                });
              } else {
                resolve({
                  associatedItem: null
                });
              }
            });
          }
      });
  } catch (error) {
    throw (error);
  }