docs: def get_urls(self):
          """
          Overload the admin's urls for MarkItUp.
          """
          entry_admin_urls = super(EntryAdminMarkItUpMixin, self).get_urls()
          urls = [
              url(r'^markitup/$',
                  self.admin_site.admin_view(self.markitup),
                  name='zinnia_entry_markitup'),
              url(r'^markitup/preview/$',
                  self.admin_site.admin_view(self.content_preview),
                  name='zinnia_entry_markitup_preview')
          ]
          return urls + entry_admin_urls