method create_view = fun ?(view = GTree.view ()) () ->
    let type_column =
      GTree.view_column ~title:"Type"
        ~renderer:(GTree.cell_renderer_text [], [("text", c_type)])
        ()
    in
    let name_column =
      GTree.view_column ~title:"Name"
        ~renderer:(GTree.cell_renderer_text [], [("text", c_name)])
        ()
    in
      i_int (view#append_column name_column);
      view#set_model (Some self#coerce);
      { cv_view = view; cv_type_c = type_column; cv_name_c = name_column; }