def round_robin(self, x, y, n_keep):
        """ Ensures all classes get representative features, not just those with strong features """
        vals = y.unique()
        scores = {}
        for cls in vals:
            scores[cls] = self.rank(x, np.equal(cls, y).astype('Int64'))
            scores[cls].reverse()
        keepers = set()
        while n_keep < len(keepers):
            for cls in vals:
                keepers.add(scores[cls].pop()[1])
        return list(keepers)
dataset/ETHPy150Open kvh/ramp/ramp/selectors.py/BinaryFeatureSelector.round_robin/swapped operands of `<`