presto-main/src/main/java/io/prestosql/operator/aggregation/CountIfAggregation.java/CountIfAggregation/input
class CountIfAggregation:    @InputFunction
    public static void input(@AggregationState LongState state, @SqlType(StandardTypes.BOOLEAN) boolean value)
    {
        if (value) {
            state.setLong(state.getLong() + 1);
        }
    }