问 MapStruct -多源集合映射

@Mapper
public interface MyMapper {
    public MyVO mapEntityToVO(MyEntity entity); // WORKS
    public ArrayList<MyVO> mapEntityListToVOList(List<MyEntity> entities); // WORKS
    public MyVO mapEntityToVO(MyEntity entity, MySecondSource source); // WORKS
    public ArrayList<MyVO> mapEntityListToVOList(List<MyEntity> entities, MySecondSource source); // DOESN'T WORK (it produces empty list)
}

public class MyMapperImpl implements MyMapper {
    [...]
    @Override
    public ArrayList<MyVO> mapEntityListToVOList(List<MyEntity> entities) {
        if ( entities == null ) {
            return null;
        ArrayList<MyVO> list = new ArrayList<MyVO>( entity.size() );
        for ( MyEntity entity : entities ) {
            list.add( mapEntityToVO ( entity ) );
        return list;
    [...]
    @Override
    public ArrayList<MyVO> mapEntityListToVOList(List<MyEntity> entities, MySecondSource source) {
       if ( entities == null && source == null) {
           return null;
       ArrayList<MyVO> arrayList = new ArrayList<MyVO>();