What is the test for requesting that further proceedings be heard before a trial judge other than the judge whose judgment or order was reviewed by the appellate court?

"At the request of a party or on its own motion an appellate court shall consider whether in the interests of justice it should direct that further proceedings be heard before a trial judge other than the judge whose judgment or order was reviewed by the appellate court. " (Code of Civ. Proc., 170.1, subd. (c).) This statutory power "should be used sparingly and only where the interests of justice require it." (People v. Gulbrandsen (1989) 209 Cal.App.3d 1547, 1562.)