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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 finalize(self):
 """ Disconnects signals and frees resources """

        self.model().sigItemChanged.disconnect(self.repoTreeItemChanged)

        selectionModel = self.selectionModel() # need to store reference to prevent crash in PySide
        selectionModel.currentChanged.disconnect(self.currentItemChanged)