presto-main/src/main/java/io/prestosql/operator/aggregation/DoubleRegressionAggregation.java/DoubleRegressionAggregation/regrIntercept
class DoubleRegressionAggregation:    @AggregationFunction("regr_intercept")
    @OutputFunction(StandardTypes.DOUBLE)
    public static void regrIntercept(@AggregationState RegressionState state, BlockBuilder out)
    {
        double result = getRegressionIntercept(state);
        if (Double.isFinite(result)) {
            DOUBLE.writeDouble(out, result);
        }
        else {
            out.appendNull();
        }
    }