/// <summary>
 /// A replacement for the declarative catalog part meant for limiting the webparts on a page to a single instance by hiding the webparts that already exist on the page.
 /// </summary>
 [Designer ( "System.Web.UI.Design.WebControls.WebParts.DeclarativeCatalogPartDesigner, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" ), AspNetHostingPermission ( SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal ), AspNetHostingPermission ( SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal )]
 public class CustomCatalog : CatalogPart
 {
  // Fields
  private WebPartDescriptionCollection _descriptions;
  private string _webPartsListUserControlPath;
  private ITemplate _webPartsTemplate;