code: def _get_ctx(self):
          
          if self._WEB_CTX_KEY not in web.ctx:
              web.ctx[self._WEB_CTX_KEY] = {
                  "javascript": {"footer": [], "header": []},
                  "css": []}
          return web.ctx.get(self._WEB_CTX_KEY)
docs: Get web.ctx object for the Template helper