PowerShell - update web.config 2

$webConfig = "C:\temp\applaunch.exe.config"
$xml = [xml] (Get-Content $webConfig)
$systemNet = $xml.configuration.configSections.sectionGroup | Where-Object {$_.name -eq "system.net"}
($systemNet.section | Where-Object {$_.name -eq "authenticationModules"}).type = "Just a test 2"
$xml.Save($webConfig)