internal static void RaiseDocumentPartHide(DocumentPart sender, DocumentPartEventArgs e)
            {
                EventHandler <DocumentPartEventArgs> handler = DocumentPartHide;

                if (handler != null)
                {
                    handler(sender, e);
                }
            }
        protected virtual void OnDocumentPartHide(DocumentPartEventArgs e)
        {
            EventHandler <DocumentPartEventArgs> handler = DocumentPartHide;

            if (handler != null)
            {
                handler(this, e);
            }
            Events.RaiseDocumentPartHide(this, e);
        }