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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 _preview(self):
 """ Preview the .ui file. Return the exit status to be passed back to the parent process. """


        from PyQt5 import QtWidgets

        app = QtWidgets.QApplication([self._ui_file])
        widget = loadUi(self._ui_file)
        widget.show()

        return app.exec_()