Dynamic Parameters with [ValidateSet()]

function Get-Info {
    [cmdletbinding()]
    param(
        [parameter(ParameterSetName="System")]
        [ValidateSet("Server","Desktop","Mainframe")]
        [string]$System
    )
    DynamicParam {
        if($PSBoundParameters["System"] -ne $null) {
            switch($System){
                "Server" {
                    $OSList = "WS2008R2","WS2012","WS2012R2","RHEL60" #...
                }
                "Desktop" {
                    $OSList = "WinXP","Win7","Win8","Win81","Win10"
                }
                "Mainframe" {
                    $OSList = "zOS","zVM","zVSE"
                }
            }
            $validateSetAttribute = new-object ValidateSet -ArgumentList $OSList
            $parameterAttribute = [parameter]::new()
            $parameterAttribute.ParameterSetName = "System"
            $attributeCollection = [System.Collections.ObjectModel.Collection[System.Attribute]]::new()
            $attributeCollection.Add($validateSetAttribute)
            $attributeCollection.Add($parameterAttribute)
            $operatingSystemParam = [System.Management.Automation.RuntimeDefinedParameter]::new('OS',[string],$attributeCollection)
            $paramDictionary = [System.Management.Automation.RuntimeDefinedParameterDictionary]::new()
            $paramDictionary.Add('OS', $operatingSystemParam)
            $paramDictionary
        }
    }
    process {
        "System: $System, OS: $($PSBoundParameters['OS'])"
    }
}