What is the test for a mentally incompetent person to stand trial?

"A criminal trial of an incompetent person violates his or her federal due process rights. [Citation.] The state Constitution and section 1367 similarly preclude a mentally incompetent defendant's criminal trial or sentencing. [Citations.] A defendant is incompetent to stand trial if the defendant lacks 'sufficient present ability to consult with his [or her] lawyer with a reasonable degree of rational understanding . . . [or] a rational as well as factual understanding of the proceedings against him [or her].' [Citations.]" (People v. Mickel (2016) 2 Cal.5th 181, 194-195 (Mickel).)