What is the test for determining which party prevailed in a personal injury action?

"'"[T]he trial court '"is given wide discretion in determining which party has prevailed on its cause(s) of action. Such a determination will not be disturbed on appeal absent a clear abuse of discretion."' [Citation.]" [Citation.] Furthermore, the trial court has the "power to determine that neither party prevailed. Requiring a determination for one party or the other in every case would encourage absurd results for if the court determines that neither party actually prevailed it would be unreasonable to award attorney fees." [Citations.]' [Citation.]" (Roden v. AmerisourceBergen Corp. (2010) 186 Cal.App.4th 620, 663.)