public async Task GetAttachmentFileForSignerAsync()
        {
            var file = await _signatureService.GetAttachmentFileForSignerAsync(_documentId, _attachmentId, _signerId, FileFormat.Pades);

            Assert.IsNotNull(file);
            AssertRequest(HttpMethod.Get, $"/signature/documents/{_documentId}/files/attachments/{_attachmentId}/signers/{_signerId}?fileFormat=pades");
        }