What is the test for claiming and issue preclusion in a personal injury action?

"Claim and issue preclusion have different requirements and effects. Claim preclusion prevents relitigation of entire causes of action. [Citation.] Claim preclusion applies only when 'a second suit involves (1) the same cause of action (2) between the same parties [or their privies] (3) after a final judgment on the merits in the first suit.' [Citation.] Issue preclusion, by contrast, prevents 'relitigation of previously decided issues,' rather than causes of action as a whole. [Citation.] It applies only '(1) after final adjudication (2) of an identical issue (3) actually litigated and necessarily decided in the first suit and (4) asserted against one who was a party in the first suit or one in privity with that party.' [Citation.] Courts have understood the ' "necessarily decided" ' prong to 'require[ ] only that the issue not have been "entirely unnecessary" to the judgment in the initial proceeding' [citation]leaving room for a decision based on two grounds to be preclusive as to both." (Samara v. Matar, supra, 5 Cal.5th at pp. 326-327.)