What is the test for unlawful possession of a controlled substance for sale?

" 'Unlawful possession of a controlled substance for sale requires proof the defendant possessed the contraband with the intent of selling it and with knowledge of both its presence and illegal character. [Citation.]' [Citations.]" (People v. Harris (2000) 83 Cal.App.4th 371, 374.) "Intent to sell may be established by circumstantial evidence." (Ibid.) On appeal, defendant contends "[t]here was insufficient evidence in this case from which a rational trier of fact could have found beyond a reasonable doubt that [he] had the requisite intent to possess the methamphetamine for sale."