What is the test for res judicata?

The Hayward opinion says, at page 229 of 117 Cal.App.2d, at page 478 of 255 P.2d: '* * * One of the principal requirements for the application of the doctrine of res judicata is: Was the issue decided in the previous action identical with the one presented in the present suit? Bernhard v. Bank of America, 19 Cal.2d 807, 813, 122 P.2d 892.

'In Stark v. Coker, 20 Cal.2d 839, 843, 129 P.2d 390, 393, the court points out that only such matters are adjudicated in a prior judgment which appear upon its face to have been adjudicated or which were necessarily included therein, and that 'when

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