According to the spec, DataModel and its subclasses must be generic.
This patch contains fixes for DataModel and all its subclasses, all generic.
Ok the patch is not appliable, I contacted jan for a new patch, if it is not possible to merge the codebases again, I will start to work the generics in manually.
That's okay. I'll look at it this weekend.
Recreated patch, this one should work
Applied the patch to the branch, revision 732556, thank for your contribution.