What is the test for proving a defendant has met its burden of showing that a cause of action has no merit?

A defendant has met its burden of showing that a cause of action has no merit if it demonstrates that one or more elements of the cause of action, even if not separately pleaded, cannot be established, or that there is a complete defense to the cause of action. ( 437c, subd. (p)(2).) "The statute of limitations operates in an action as an affirmative defense. [Citation.]" (Drexler v. Petersen (2016) 4 Cal.App.5th 1181, 1188.) Once the defendant meets this burden, the burden shifts to the plaintiff to prove the existence of a triable issue of fact regarding that element of its cause of action or that defense. (Ibid.)