The bf_partOf PropertyShape for Items should be limited to BoundCollections

[rjyounes]

One way to implement this is:

:BoundCollectionForm
a sh:NodeShape ;
sh:node :ItemForm ; # "inherits" all constraints from ItemForm
# adds additional constraints particular to the BoundCollection
sh:targetClass arm:BoundCollection ;
sh:property :BoundCollectionForm_bf_hasPart_arm_Item ;
.

:BoundCollectionForm_bf_hasPart_arm_Item
sh:class bf:Item ;
etc.

The ItemForm would omit this property shape.

For now in VitroLib will use workaround by hard-coding the domain. See ld4l-labs/vitrolib#211.