sqlserver.rb DISM command references undefined $LocalSource variable

Install-WindowsFeature  NET-Framework-Core

Write-Host "Installing .Net Framework 3.5, do not close this prompt..."

DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:$LocalSource | Out-Null

$Result = Dism /online /Get-featureinfo /featurename:NetFx3

If($Result -contains "State : Enabled")

{

    Write-Host "Install .Net Framework 3.5 successfully."

}

Else

{

    Write-Host "Failed to install Install .Net Framework 3.5,please make sure the local source is correct."

}