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