code: def conflicting_pairs(left, right):
      
      objects = left._objects & right._objects
      properties = left._properties & right._properties
      difference = left._pairs ^ right._pairs
      for o in objects:
          for p in properties:
              if (o, p) in difference:
                  yield (o, p)
docs: Yield all ``(object, property)`` pairs where the two definitions disagree.