presto-main/src/main/java/io/prestosql/operator/project/SelectedPositions.java/SelectedPositions/subRange
class SelectedPositions:    public SelectedPositions subRange(int start, int end)
    {
        checkPositionIndexes(start, end, size);

        int newOffset = this.offset + start;
        int newLength = end - start;
        return new SelectedPositions(isList, positions, newOffset, newLength);
    }