What is the test for ineffective assistance of counsel?

"In order to establish a claim for ineffective assistance of counsel, a defendant must show that his or her counsel's performance was deficient and that the defendant suffered prejudice as a result of such deficient performance. [Citation.] To demonstrate deficient performance, defendant bears the burden of showing that counsel's performance ' " ' "fell below an objective standard of reasonableness . . . under prevailing professional norms." ' " ' [Citation.] To demonstrate prejudice, defendant bears the burden of showing a reasonable probability that, but for counsel's deficient performance, the outcome of the proceeding would have been different. [Citations.]" (People v. Mickel (2016) 2 Cal.5th 181, 198.)