What is the test for determining whether a person is "socially situated" for purposes of a claim under the California Civil Rights Act?

affects two or more similarly situated groups in an unequal manner." [Citations.] This initial inquiry is not whether persons are similarly situated for all purposes, but "whether they are similarly situated for purposes of the law challenged." [Citation.] In other words, we ask at the threshold whether two classes that are different in some respects are sufficiently similar with respect to the laws in question to require the government to justify its differential treatment of these classes under those laws." ( People v. McKee (2010) 47 Cal.4th 1172, 1202, 104 Cal.Rptr.3d 427, 223 P.3d 566.)