def estimate(self, blocks):
        lengths = numpy.fromiter((len(ids) for ids in blocks), int)
        return numpy.sum((lengths * self.multiplier) *
                         (1 - lengths * self.multiplier) /
                         2)
dataset/ETHPy150Open datamade/dedupe/dedupe/training.py/DedupeBlockLearner.estimate/swapped operands of `-`