System.Object
   System.MarshalByRefObject
      System.ComponentModel.Component
         System.Windows.Forms.Control
            GrapeCity.ActiveReports.Design.DdrDesigner.Designers.ReportComponentDesigner
               GrapeCity.ActiveReports.Design.DdrDesigner.Designers.ReportItemDesigner
                  GrapeCity.ActiveReports.Design.DdrDesigner.Designers.ReportItemContainerDesigner
                     GrapeCity.ActiveReports.Design.DdrDesigner.Designers.CustomReportItemDesigner
                        GrapeCity.ActiveReports.Dashboard.Design.ReportItemDesignerBase

Reference

GrapeCity.ActiveReports.Design.Win Assembly