What is the test for making a party an indispensable party in a civil matter?

This reasoning is in harmony with that of the California cases dealing with the subject. Bowles v. Superior Court, 44 Cal.2d 574, 583, 283 P.2d 704, 710: 'Where persons are so interested in the controversy that they should normally be made parties in order to enable the court to do complete justice, but their interests are separable from the rest, they are necessary but not indispensable parties. On the other hand, one may be an indispensable party if his interest in the subject matter of the controversy is of such a nature that a final decree cannot be rendered between the other parties to the suit without inevitably affecting that interest.'

Page 519