presto-main/src/main/java/io/prestosql/operator/project/SelectedPositions.java/SelectedPositions/SelectedPositions
class SelectedPositions:    private SelectedPositions(boolean isList, int[] positions, int offset, int size)
    {
        this.isList = isList;
        this.positions = requireNonNull(positions, "positions is null");
        this.offset = offset;
        this.size = size;

        checkArgument(offset >= 0, "offset is negative");
        checkArgument(size >= 0, "size is negative");
        if (isList) {
            checkPositionIndexes(offset, offset + size, positions.length);
        }
    }