docs: async def get_value(self):
          """
          Get the value from the API. Make sure to use a lock in order not to
          fetch the value twice at the same time.
          """
  
          cc = self.request.custom_content
  
          async with self.lock:
              if self.content_key not in cc:
                  cc[self.content_key] = await self.call_api()
  
          return cc[self.content_key]