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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 closeEvent(self, event):
 """ Terminates the child process on close. """

        self.stop_process()
        self.backend.stop()
        try:
            self.modes.remove('_LinkHighlighter')
        except KeyError:
            pass  # already removed
        super(OutputWindow, self).closeEvent(event)