code: def get_api_link(self):
          
          url = self._api_link
          if url:
              qs = self.get_qs()
              url = "%s?type=choices" % url
              if qs:
                  url = "%s&amp;%s" % (url, u'&amp;'.join([u'%s=%s' % (k, urllib.quote(unicode(v).encode('utf8'))) \
                                                          for k, v in qs.items()]))
                  url = "%s&amp;%s" % (url, u'&amp;'.join([u'exclude=%s' % x \
                                                          for x in qs.keys()]))
          return url
docs: Adds a query string to the api url. At minimum adds the type=choices
          argument so that the return format is json. Any other filtering
          arguments calculated by the `get_qs` method are then added to the
          url. It is up to the destination url to respect them as filters.