/// <summary>
/// Validate the field passed in
/// </summary>
/// <param name="document"></param>
/// <param name="node"></param>
/// <param name="useRelative"></param>
private static HtmlNode ValidateDefaults(HtmlDocument document, HtmlNode node, bool useRelative)
{
document = document.NotNull();
if (useRelative)
{
node = node.NotNull();
}
return useRelative ? node : document.DocumentNode;
}