Whatisnotdocumentedisthatcallables$validate_sidand$update_timestamparesupportedsincePHP7.0.fortheprototypeof"boolsession_set_save_handler(callable$open,callable$close,callable$read,callable$write,callable$destroy,callable$gc[,callable$create_sid[,callable$validate_sid[,callable$update_timestamp]]])".validate_sid($sessionId)Thiscallbackistovalidate$sessionId.Itsreturnvalueshouldbetrueforval...