presto-main/src/main/java/io/prestosql/operator/aggregation/minmaxby/BooleanAndBlockPositionStateSerializer.java/BooleanAndBlockPositionStateSerializer/readFirstField
class BooleanAndBlockPositionStateSerializer:    @Override
    void readFirstField(Block block, int position, BooleanAndBlockPositionValueState state)
    {
        state.setFirst(firstType.getBoolean(block, position));
    }