class AttachmentUploadResult {

    @Override
    public String toString() {
        return "AttachmentUploadResult{" +
                "target=" + target +
                ", successfulUploads=" + successfulUploads +
                ", failedUploads=" + failedUploads +
                '}';
    }

    public  AttachmentUploadResult(T target);
    private  AttachmentUploadResult(T target,
                                   Set<AttachmentUploadRequest.Item> successfulUploads,
                                   Map<AttachmentUploadRequest.Item, Throwable> failedUploads);

}