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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 run(self, clf):
 """Run correlation-based voxel selection in master-worker model. Sort the voxels based on the cross-validation accuracy of their correlation vectors Parameters clf: classification function the classifier to be used in cross validation Returns ------- results: list of tuple (voxel_id, accuracy) the accuracy numbers of all voxels, in accuracy descending order the length of array equals the number of voxels """

        rank = MPI.COMM_WORLD.Get_rank()
        if rank == self.master_rank:
            results = self._master()
            # Sort the voxels
            results.sort(key=lambda tup: tup[1], reverse=True)
        else:
            self._worker(clf)
            results = []
        return results