def installParcel(parcel, oldVersion=None):
    ...
    publishedFreeBusy = UnionCollection.update(parcel, 'publishedFreeBusy')
    unpublishedFreeBusy = DifferenceCollection(parcel, "unpublishedFreeBusy",
        sources=[schema.ns('osaf.pim', parcel.itsView).allEventsCollection, publishedFreeBusy]
    )

I get:

  File "c:\work\osaf\chandler\parcels\osaf\sharing\__init__.py", line 98, in installParcel
    sources=[schema.ns('osaf.pim', view).allEventsCollection,
  File "c:\work\osaf\chandler\parcels\osaf\pim\collections.py", line 197, in __init__
    super(WrapperCollection, self).__init__(*args, **kwds)
  File "c:\work\osaf\chandler\parcels\osaf\pim\items.py", line 189, in __init__
    super(ContentItem, self).__init__(*args, **kw)
  File "c:\work\osaf\chandler\application\schema.py", line 651, in __init__
    itsView = itsParent.itsView
AttributeError: 'str' object has no attribute 'itsView'