* Authentication may require to reply to an authentication challenge,
* by sending again the request, with credentials.
*/
private EXistResult sendOnce(final URI uri, final HttpRequest request, final RequestParser parser) throws HttpClientException
{
final EXistResult result;
if(parser.getSendAuth()) {
result = sendOnceWithAuth(uri, request, parser.getCredentials());
} else {
HttpConnection conn = null;
try {
conn = new ApacheHttpConnection(uri);
final EXistResult firstResult = new EXistResult(context);
final HttpResponse response = request.send(firstResult, conn, null);
if(response.getStatus() == 401) {
conn.disconnect();
result = sendOnceWithAuth(uri, request, parser.getCredentials());
} else {