What is the legal test for a motion to disqualify a judge?

whom it was filed may order it stricken." (Code Civ. Proc. 170.4, subd. (b).) Code of Civil Procedure section 170.3, subdivision (d) sets forth "the exclusive means of challenging a denial of a motion to disqualify a judge." (People v. Hull (1991) 1 Cal.4th 266, 275.) Pursuant to this statute, "[t]he determination of the question of the disqualification of a judge is not an appealable order and may be reviewed only by a writ of mandate from the appropriate court of appeal sought only by the parties to the proceeding. The petition for the writ shall be filed and served within 10 days after service of written notice of entry of the court's order determining the question of disqualification." (Code Civ. Proc. 170.3, subd. (d).)