Clears the actions for this widget.

def clear(self, autoBuild=True):
        """
        Clears the actions for this widget.
        """
        for action in self._actionGroup.actions():
            self._actionGroup.removeAction(action)
        
        action = QAction('', self)
        action.setObjectName('place_holder')
        self._actionGroup.addAction(action)
        if autoBuild:
            self.rebuild()