Distinguishing Alvarado v. Dart Container Corp. of California (2018) 4 Cal.4th 542, this decision holds that in calculating the “regular rate of pay” for overtime work by a “dual rate” employee, the employer is not required to use the weighted average method of computing regular rate of pay but may instead calculate regular rate of pay by using the rate-in-effect method which treats the regular rate of pay as the rate at which the employee was being compensated at the time he began the overtime hours.