Need help with SOAP request for guest operations

I'm working on a php script to do some automation. This is using the standard SOAP/WSDL and PHP. Mostly things are going well, but I have ran into an issue with guest operations. Can anyone either post the XML request/response or give an example using the MOB. I've been working with listFilesInGuest, but anything will do. I just need to understand how the guest authorization works. I've been able to use pyvmomi to get this, but I can't seem to figure out how to output the request/response in python. My requirement is for PHP so I can't move to python either.

Any help is greatly appreciated.