What is the test for section 654 of the California Code of Criminal Procedure when a defendant is charged with two separate crimes?

Under section 654, "[a]n act or omission that is punishable in different ways by different provisions of law shall be punished under the provision that provides for the longest potential term of imprisonment, but in no case shall the act or omission be punished under more than one provision." ( 654, subd. (a).) "The purpose of section 654 is to prevent multiple punishment for a single act or omission, even though that act or omission violates more than one statute and thus constitutes more than one crime. Although the distinct crimes may be charged in separate counts and may result in multiple verdicts of guilt, the trial court may impose sentence for only one offensethe one carrying the highest punishment. [Citation.] The 'act' necessary to invoke section 654 need not be an act in the ordinary sense of a separate, identifiable, physical incident, but may instead be a 'course of conduct' or series of acts violating more than one statute and comprising an indivisible transaction punishable under more than one statute." (People v. Liu, supra, 46 Cal.App.4th at p. 1135, fn. omitted.)