8. Default Codeunits The platform ships with a couple default codeunits, that help manage the CMS data. Basic Menu Name: com.tsnocode.core.cms.BasicMenu Generates a dynamic menu, with option of one layer of sub-element, and marks the active page.   Page handler Name: com.tsnocode.core.cms.PageEventHandler Helps maintain redirects, when a pages url changes, by automatically added the old url to the redirects entity.   Media handler Name: com.tsnocode.core.cms.MediaEventHandler Helps write images and videos to disk, and down sampling videos.   Preview page Name: com.tsnocode.core.cms.ShowPage Resets the cache and shows a page.