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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 clearFilter(self):
 """ Clear all filters. """

        if self._dataFrameOriginal is not None:
            self.layoutAboutToBeChanged.emit()
            self._dataFrame = self._dataFrameOriginal
            self._dataFrameOriginal = None
            self.layoutChanged.emit()