A challenging client is somebody who probably is really upset, really frustrated, and what I would do is I would just keep calm, stay calm, and the most important thing is to make that person happy and to figure out any way you can to do that. So I would always figure out what the issue is, what the problem is, and then I would fix it, and generally when I run into situations like that, the customers always end up happy and they're fine, so I just make sure that happens.