presto-main/src/main/java/io/prestosql/operator/project/GeneratedPageProjection.java/GeneratedPageProjection/project
class GeneratedPageProjection:    @Override
    public Work<Block> project(ConnectorSession session, DriverYieldSignal yieldSignal, Page page, SelectedPositions selectedPositions)
    {
        blockBuilder = blockBuilder.newBlockBuilderLike(null);
        try {
            return (Work<Block>) pageProjectionWorkFactory.invoke(blockBuilder, session, page, selectedPositions);
        }
        catch (Throwable e) {
            throw new RuntimeException(e);
        }
    }