What is the test for unlawful possession of methamphetamine?

To establish unlawful possession of methamphetamine, the People were required to prove four elements: "(1) defendant exercised control over or the right to control an amount of methamphetamine; (2) defendant knew of its presence; (3) defendant knew of its nature as a controlled substance; and (4) the substance was in an amount usable for consumption." (People v. Tripp (2007) 151 Cal.App.4th 951, 956, italics added; see 11377, subd. (a).) The jury was instructed accordingly.