http://developers.de/blogs/damir_dobric/archive/2009/04/13/using-of-factory-in-pex.aspxPex (program exploration tool)  a great capability to create factory helper classes, when PEX itself is not able to guess how to do that automatically. To make this explicitly useful, you have to now in which case PEX can do it for you. Here is oneenCommunityServer 2008 SP1 (Build: 30619.63)