def run(self, table):
        column = table.columns[self._column_name]

        data = column.values_without_nulls()
        mean = self._mean.run(table)

        return sum((n + mean) ** 2 for n in data) / (len(data) - 1)
dataset/ETHPy150Open wireservice/agate/agate/aggregations/variance.py/Variance.run/operator `-` -> `+`