What is the test for denying a request to admit a plaintiff in a civil case?

Subdivision (b) of section 2033.420 provides: "The court shall make this order [to pay reasonable expenses] unless it finds any of the following: [] (1) An objection to the request was sustained or a response to it was waived under Section 2033.290. [] (2) The admission sought was of no substantial importance. [] (3) The party failing to make the admission had reasonable ground to believe that that party would prevail on the matter. [] (4) There was other good reason for the failure to admit." "In evaluating whether a 'good reason' exists for denying a request to admit, 'a court may properly consider whether at the time the denial was made the party making the denial held a reasonably entertained good faith belief that the party would prevail on the issue at trial.' " (Laabs v. City of Victorville (2008) 163 Cal.App.4th 1242, 1276.)