What is the test for sanity of an attorney at a disciplinary proceeding?

Even if it should be determined that by analogy to cases such as Pate v. Robinson, supra, 383 U.S. 375, 86 S.Ct. 836, and People v. Pennington, supra, 66 Cal.2d 508, 58 Cal.Rptr. 374, 426 P.2d 942, an attorney is entitled to a hearing upon the issue of his sanity at the time of disciplinary proceeding hearings against him upon the presentation of substantial evidence that he was incapable, because of mental illness, of understanding the nature of the proceedings or participating in his defense, petitioner has presented no such evidence.