from images you can see from the link, use of  generate list from: Solid::Device::listFromType(Solid::Type::StorageVolume, QString())
converted to Solid::StorageVolume object for print QString datas of the volume (look at image 3 offer a view in the concerned code), failed to do the job by add some empty occurences (bug number one) in the list, and one doubles (bug number two).
And also (bug number 3), later, if you use the Solid::StorageAccess (do try it really...), with udi search for a storage device selected, ZFS formated partitions never show the listpath() (the mount point) of the partition.
 

Reproducible: Always

Steps to Reproduce:
1. follow the kde4 tutos for use solid::device for read storage and do the code from ther...
2. use/format a partition disk in ZFS, mixed on the same Hard drive with other ext4 or other format (and do use zfs packages for that)
3. so use the Solid::Device::listFromType(....) same the API explain it
4. then look at the occurrences inside the list generated... it has some doubles and maybe some copy for this ZFS partition
5. use Solid::StorageAccess for try to see the mount point of the ZFS volume (good luck for see them...)

Actual Results:  
1. in the QList<Solid::Device> list generate, there is some empty occurences.
2. in this list, for ZFS partitions of disk who are mixed with after format partitions, there is a double.
3. when use Solid:StorageAccess with ZFS partitions, listPath() member function is empty instead of show you the mount point of the partition.

Expected Results:  
1. no empty occurrences, just what the function is intend to search for
2. no other doubles of occurrences
3. just show what he has to show: the mount point.

I paste 3 images, 2 of them is a view of the output (these output are the same from a qDebug() message), then picture nb 3 is a view of the concerned code who is made from official KDE4 (so old one... links are broken... look at this please)  tutos pages for these "solid framework".
I try to find help on IRC channel in kde-devel without any success (no one seems to know).