public async Task <string> CreateSignatureAsync(byte[] data, CancellationToken cancellationToken)
            {
                ProjectsResource.ServiceAccountsResource.SignBlobRequest request = CreateRequest(data);
                SignBlobResponse response = await request.ExecuteAsync(cancellationToken).ConfigureAwait(false);

                return(response.Signature);
            }
            private ProjectsResource.ServiceAccountsResource.SignBlobRequest CreateRequest(byte[] data)
            {
                SignBlobRequest body = new SignBlobRequest {
                    BytesToSign = Convert.ToBase64String(data)
                };
                string account = $"projects/-/serviceAccounts/{Id}";

                ProjectsResource.ServiceAccountsResource.SignBlobRequest request =
                    _iamService.Projects.ServiceAccounts.SignBlob(body, account);
                return(request);
            }