Powershell Change a Virtual Server Default Pool

from this example: http://techieespoint.in/f5-big-ip-automation-through-powershell/

they call it like this: $AuthObj.LocalLBVirtualServer.set_default_pool_name(“testvirtualserver”,$VIPPoolName)

which matches here: https://devcentral.f5.com/wiki/iControl.LocalLB__VirtualServer__set_default_pool_name.ashx

you first do the virtual server and then the pool, it is difficult to judge but /Common/Test-Pool feels like a poolname.