Where is EventSinkActivity ?

First of all I'm new in WWF.

I was readinghttp://www.dennispi.com/2005/09/local-communication-servic_112803113054978800.html. There and more places i saw references to EventSinkActivity but I didn't find it in my system (I'm using Visual Studio 2005 with Windows Workflow Foundation installed). Can anyone tell me why?

Thanks.

[537 byte] By [silviutis] at [2007-12-24]