Part of bzrlib.repository View In Hierarchy
An iterable yielding the contents of many lists as one list.
Each iterator made from this will reflect the current contents of the lists at the time the iterator is made.
This is used by Repository's _make_parents_provider implementation so that it is safe to do:
pp = repo._make_parents_provider() # uses a list of fallback repos pp.add_fallback_repository(other_repo) # appends to that list result = pp.get_parent_map(...) # The result will include revs from other_repo