/// <summary>
/// Adds and updates the keys/value based on <paramref name="propertiesToSet"/>.
/// Any other keys are uneffected.
/// </summary>
/// <param name="h"></param>
/// <param name="propertiesToSet"></param>
public static void SetHashtable(this Hashtable h, Hashtable propertiesToSet)
{
var customProps = propertiesToSet.StripToStringKeys() as Hashtable;
h.Merge(customProps);
h.StripKeysWithNullValues();
}