How to use the orange3.Orange.canvas.scheme.widgetsscheme.WidgetManager.Materialized function in Orange3

# widget initialization
        assert isinstance(state, WidgetManager.Delayed)
        if state in self.__init_queue:
            self.__init_queue.remove(state)

        node = state.node

        widget = self.create_widget_instance(node)

        self.__widgets.append(widget)
        self.__widget_for_node[node] = widget
        self.__node_for_widget[widget] = node

        self.__initialize_widget_state(node, widget)

        state = WidgetManager.Materialized(node, widget)
        self.__initstate_for_node[node] = state
        self.widget_for_node_added.emit(node, widget)

        return state

widget.__init__()
            except Exception:
                sys.excepthook(*sys.exc_info())
                msg = traceback.format_exc()
                msg = "Could not create {0!r}\n\n{1}".format(node.description.name, msg)
                # remove state tracking for widget ...
                del self.__widget_for_node[node]
                del self.__node_for_widget[widget]
                del self.__widget_processing_state[widget]

                # ... and substitute it with a mock error widget.
                widget = mock_error_owwidget(node, msg)
                self.__widget_for_node[node] = widget
                self.__node_for_widget[widget] = node
                self.__widget_processing_state[widget] = 0
                self.__initstate_for_node[node] = WidgetManager.Materialized(
                    node, widget
                )

        self.__initstate_for_node[node] = WidgetManager.Materialized(node, widget)
        # Clear Initializing flag
        self.__widget_processing_state[widget] &= ~WidgetManager.Initializing

        node.title_changed.connect(widget.setCaption)

        # Widget's info/warning/error messages.
        widget.messageActivated.connect(self.__on_widget_state_changed)
        widget.messageDeactivated.connect(self.__on_widget_state_changed)

        # Widget's statusTip
        node.set_status_message(widget.statusMessage())
        widget.statusMessageChanged.connect(node.set_status_message)

msg = "Could not create {0!r}\n\n{1}".format(node.description.name, msg)
                # remove state tracking for widget ...
                del self.__widget_for_node[node]
                del self.__node_for_widget[widget]
                del self.__widget_processing_state[widget]

                # ... and substitute it with a mock error widget.
                widget = mock_error_owwidget(node, msg)
                self.__widget_for_node[node] = widget
                self.__node_for_widget[widget] = node
                self.__widget_processing_state[widget] = 0
                self.__initstate_for_node[node] = WidgetManager.Materialized(
                    node, widget
                )

        self.__initstate_for_node[node] = WidgetManager.Materialized(node, widget)
        # Clear Initializing flag
        self.__widget_processing_state[widget] &= ~WidgetManager.Initializing

        node.title_changed.connect(widget.setCaption)

        # Widget's info/warning/error messages.
        widget.messageActivated.connect(self.__on_widget_state_changed)
        widget.messageDeactivated.connect(self.__on_widget_state_changed)

        # Widget's statusTip
        node.set_status_message(widget.statusMessage())
        widget.statusMessageChanged.connect(node.set_status_message)

        # Widget's progress bar value state.
        widget.progressBarValueChanged.connect(node.set_progress)