/// <summary>
/// Append CSS class to the <![CDATA[<head>]]> element
/// </summary>
/// <param name="html">HTML helper</param>
/// <param name="part">CSS class</param>
public static void AppendPageCssClassParts(this IHtmlHelper html, string part)
{
IPageHeadBuilder pageHeadBuilder = ServiceProviderFactory.ServiceProvider.GetService <IPageHeadBuilder>();
pageHeadBuilder.AppendPageCssClassParts(part);
}