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