The period in milli seconds during which the nonce sent by server is valid.
The period in milli seconds during which the nonce sent by server is valid. After this period
even if the auth digest matches correctly the authentication will fail.
A useful usability would be to return something like "5 seconds" where seconds function is defined in TimeHelpers.
The default value returned is 30 seconds.
(Since version 2.8.0) use productIterator instead