def __unicode__(self):
        delta = self.previous - self.value
        sign = '-' if delta < 0 else '+'
        return '"{0}" = "{0}" {1} %({2})s'.format(self.field, sign, self.context_id)
dataset/ETHPy150Open datastax/python-driver/cassandra/cqlengine/statements.py/CounterUpdateClause.__unicode__/swapped operands of `-`