What is the test for relying on "class of one" theory when plaintiff is not in a protected class?

he is a member of a suspect class, his only route to establish his equal protection is the second option, often referred to as a "class of one." Village of Willowbrook v. Olech, 528 U.S. 562, 564 (2000) (Discussing reliance on "class of one" theory when plaintiff is not in a protected class). To state a claim under this theory, a plaintiff must allege they have "been intentionally treated differently from others similarly situated and that there is no rational basis for the difference in treatment." Id.