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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_action(self, create=False):
 """ Get the shared widget action for this widget. This API is used to support widgets in tool bars and menus. Parameters create : bool, optional Whether to create the action if it doesn't already exist. The default is False. Returns ------- result : QWidgetAction or None The cached widget action or None, depending on arguments. """

        action = self._widget_action
        if action is None and create:
            action = self._widget_action = QWidgetAction(None)
            action.setDefaultWidget(self.widget)
        return action