What is the test for an attorney fee for enforcing an existing right to sue for damages?

Northern California v. California Regional Water Quality Control Bd., North Coast Region (2010) 183 Cal.App.4th 330, 363.) A trial court must assess the significance of the benefit as well as its impact "'from a realistic assessment, in light of all the pertinent circumstances, of the gains which have resulted in a particular case.' [Citation.] The 'extent of the public benefit need not be great to justify an attorney fee award.' [Citation.]" (Center for Biological Diversity v. County of San Bernardino (2010) 185 Cal.App.4th 866, 894.)

Moreover, the enforcement of an existing right "does not mean that a substantial benefit to the public cannot result. Attorney fees have consistently been awarded for the enforcement of well-defined, existing obligations. [Citations.]" (Press v. Lucky Stores, Inc. (1983) 34 Cal.3d 311, 318.)