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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 show_busy(self):
 """Lock buttons and enable the busy cursor."""

        self.progress_bar.show()
        self.parent.pbnNext.setEnabled(False)
        self.parent.pbnBack.setEnabled(False)
        self.parent.pbnCancel.setEnabled(False)
        self.parent.repaint()
        enable_busy_cursor()
        QgsApplication.processEvents()