Add or update to hashtable

AddOrUpdate.ps1

function getOrUpdateValue {
    [CmdletBinding()]
    param(
        $Hashtable,
        $Key,
        $DefaultValue
    )

    if ($Hashtable.ContainsKey($Key)) {
        # do not enumerate so we get the same thing back
        # even if it is a collection
        $PSCmdlet.WriteObject($Hashtable.$Key, $false)
    }
    else {
        $Hashtable.Add($Key, $DefaultValue)
        # do not enumerate so we get the same thing back
        # even if it is a collection
        $PSCmdlet.WriteObject($DefaultValue, $false)
    }
}