code: def get_announcements(self, site=None, num=10, age=20):
          
          url = BASE_URL_TSQUARE + 'announcement/'
          if site:
              url += 'site/{}.json?n={}&d={}'.format(site.id, num, age)
          else:
              url += 'user.json?n={}&d={}'.format(num, age)
          request = self._session.get(url)
          request.raise_for_status()
          announcement_list = request.json()['announcement_collection']
          return map(lambda x: TSquareAnnouncement(**x), announcement_list)
docs: Gets announcements from a site if site is not None, or from every
          site otherwise. Returns a list of TSquareAnnouncement objects.
          @param site_obj (TSquareSite) If non-None, gets only the announcements
                                        from that site. If none, get anouncements
                                        from all sites.
          @param num - The number of announcements to fetch. Default is 10.
          @param age - 'How far back' to go to retreive announcements. Default
                       is 20, which means that only announcements that are
                       less than 20 days old will be returned, even if there
                       less than 'num' of them.
          @returns - A list of TSquareAnnouncement objects. The length will be
                     at most num, and it may be less than num depending on
                     the number of announcements whose age is less than age.