How to set FTP response code?

Hi!

When sending my document over HTTP I use pub.flow:setResponseCode in appropriate handler and everything works fine. When sending the same document over FTP I don´t know how to set the response code. (My FTP-client looks funny, but I can see that my document is being processed in Trading Networks.) pub.flow:setResponseCode doesn´t seem to work when using FTP, I get nullpointer exception in the Activity Log. How do I set the response code when using FTP?

Thank you!