This artist rendering shows Apple CEO Tim Cook on the witness stand during a trial in San Ramon, Calif., on Friday, May 21, 2021. Cook described the company's ironclad control over its mobile app store as a way to keep things simple for customers while protecting them against security threats and privacy intrusions during Friday testimony denying allegations he has been running an illegal monopoly. The rare courtroom appearance by one of the world's best-known executives came during the closing phase of a three-week trial revolving an antitrust case brought by Epic Games, maker of the popular video game Fortnite. (Vicki Behringer via AP)

In this courtroom sketch Apple CEO Tim Cook, left, is cross examined by Epic Games lawyer Gary Bornstein, second from right, during a trial in San Ramon, Calif., on Friday, May 21, 2021. Cook described the company's ironclad control over its mobile app store as a way to keep things simple for customers while protecting them against security threats and privacy intrusions during Friday testimony denying allegations he has been running an illegal monopoly. The rare courtroom appearance by one of the world's best-known executives came during the closing phase of a three-week trial revolving around an antitrust case brought by Epic Games, maker of the popular video game Fortnite. (Vicki Behringer via AP)

Apple CEO Tim Cook leaves the Ronald V. Dellums building in Oakland, Calif., after testifying in a federal court case brought by Epic Games on Friday, May 21, 2021. Epic, maker of the video game Fortnite, charges that Apple has transformed its App Store into an illegal monopoly. (AP Photo/Noah Berger)

Apple CEO Tim Cook leaves the Ronald V. Dellums building in Oakland, Calif., after testifying in a federal court case brought by Epic Games on Friday, May 21, 2021. Epic, maker of the video game Fortnite, charges that Apple has transformed its App Store into an illegal monopoly. (AP Photo/Noah Berger)

Apple CEO Tim Cook walks through the Ronald V. Dellums building, Friday, May 21, 2021, in Oakland, Calif. Cook is expected to take the witness stand Friday to defend the company's iPhone app store against charges that it has grown into an illegal monopoly — one far more profitable than his predecessor Steve Jobs envisioned when it opened up 13 years ago. (AP Photo/Noah Berger)

This courtroom sketch shows Apple CEO Tim Cook being questioned by U.S. District Court Judge Yvonne Gonzalez Rogers during a trial in San Ramon, Calif., on Friday, May 21, 2021. Cook described the company's ironclad control over its mobile app store as a way to keep things simple for customers while protecting them against security threats and privacy intrusions during Friday testimony denying allegations he has been running an illegal monopoly. The rare courtroom appearance by one of the world's best-known executives came during the closing phase of a three-week trial revolving an antitrust case brought by Epic Games, maker of the popular video game Fortnite. (Vicki Behringer via AP)