docs: def _extract_asset_urls(self, asset_ids):
          """
          Extract asset URLs along with asset ids.
  
          @param asset_ids: List of ids to get URLs for.
          @type assertn: [str]
  
          @return: List of dictionaries with asset URLs and ids.
          @rtype: [{
              'id': '<id>',
              'url': '<url>'
          }]
          """
          dom = get_page(self._session, OPENCOURSE_ASSET_URL,
                         json=True,
                         ids=quote_plus(','.join(asset_ids)))
  
          return [{'id': element['id'],
                   'url': element['url'].strip()}
                  for element in dom['elements']]