In a REST persistent script custom endpoint, how to return HTTP status code other than 200?

[lekanneer]

I'm writing my own custom endpoint which is needed to be persistent. So it is based on the PersistentServerConnectionApplication class because performance is important. But how to return other HTTP status codes other than 200? I have to check some authorization within my custom endpoint so I rather want to use a status code in the range of 4xx if something goes wrong.