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This class can be used to display interstitial advertising. It generates HTML and JavaScript that makes an advertising page appear on the current page and then automatically disappears if the user clicks on the skip link or does not click on the advertising after a few seconds. The advertising display time is configurable. The same user may also not be exposed to the same advert for until a given period. The class may invoke a given callback function when the user clicks on the advert or in the skip links.