I run the `check_links` shell and found the following broken link,
1. `ERROR `/api/java/' not found` seems reachable in remote ['ExecutionEnvironment'|https://ci.apache.org/projects/flink/flink-docs-master/concepts/flink-architecture.html#flink-application-execution] (PS, It only broken in my local, I have already built the javadoc in my local.)
2. For `ERROR `/dev/python/table-api-users-guide/udfs.html' not found.`, I did not found any documents use this.
3. It is really broken. We should use
4. It is same as the first case.