old_contents: from .index import IndexView
  from .current import CurrentView
  from .history import HistoryView
  from .commit import CommitView
  from .read_only import ReadOnlyView
  
new_contents: from .index import IndexView
  from .current import CurrentView
  from .history import HistoryView
  from .commit import CommitView
  from .read_only import ReadOnlyView
  from .passthrough import PassthroughView
  
subject: Add the PassthroughView to views/__init__.py