What is the test for ineffective assistance of counsel?

"Unless a defendant establishes the contrary, we shall presume that 'counsel's performance fell within the wide range of professional competence and that counsel's actions and inactions can be explained as a matter of sound trial strategy.' [Citation.] If the record 'sheds no light on why counsel acted or failed to act in the manner challenged,' an appellate claim of ineffective assistance of counsel must be rejected 'unless counsel was asked for an explanation and failed to provide one, or unless there simply could be no satisfactory explanation.' " (People v. Ledesma, supra, 39 Cal.4th at p. 746.) A failure to make a futile or nonmeritorious motion does not constitute ineffective assistance. (People v. Szadziewicz (2008) 161 Cal.App.4th 823, 836.)