What is the test for a motion to disqualify a district attorney from performing his authorized duty?

"[A] motion to disqualify a district attorney from performing an authorized duty . . . may not be granted unless the evidence shows that a conflict of interest exists that would render it unlikely that the defendant would receive a fair trial." ( 1424, subd. (a)(1).) "'The statute "articulates a two-part test: '(i) is there a conflict of interest?; and (ii) is the conflict so severe as to disqualify the district attorney from acting?'"' [Citation.] The defendant 'bear[s] the burden of demonstrating a genuine conflict; in the absence of any such conflict, a trial court should not interfere with the People's prerogative to select who is to represent them.' [Citation.] That burden is especially heavy where . . . the defendant seeks to recuse not a single prosecutor but the entire office." (People v. Trinh (2014) 59 Cal.4th 216, 229.)