How can I create an Activity that encompasses other Activities?

SO. I am starting out in WF4 and I have a design/flow question. I created a custom code activity that takes an "in argument" and stores a result to an "out argument". Pretty basic. Next I use an "If" flow operator using the result of the "out argu开发者_开发技巧ment". All of that works great. But my question is, can I create a custom code activity that combines these two steps together? I looked into extending from the System.Activities.Statements.If class, but the class is sealed. Any suggestions?

Thanks.

---

It looks like Custom Control Flow. You may find Authoring Custom Control Flow Activities in WF 4 article to be useful.