gobject.GObject
     +--gtk.Object
     |      +--gtk.Widget
     |         +--gtk.Container
     |             +--goocanvas.Canvas
     |
     +--goocanvas.ItemSimple (implements goocanvas.Item)
     |     +--goocanvas.Ellipse
     |     +--goocanvas.Grid
     |     +--goocanvas.Image
     |     +--goocanvas.Path
     |     +--goocanvas.Polyline
     |     +--goocanvas.Rect
     |     +--goocanvas.Text
     |     +--goocanvas.Group
     |
     +--goocanvas.ItemModelSimple (implements goocanvas.ItemModel)
     |     +--goocanvas.EllipseModel
     |     +--goocanvas.GridModel
     |     +--goocanvas.ImageModel
     |     +--goocanvas.PathModel
     |     +--goocanvas.PolylineModel
     |     +--goocanvas.RectModel
     |     +--goocanvas.TextModel
     |     +--goocanvas.GroupModel
     |
     +--goocanvas.Style

gobject.GInterface
     +--goocanvas.Item
     +--goocanvas.ItemModel