What is the test for making a testimonial statement to a police officer?

"'[A]lthough the high court has not agreed on a definition of "testimonial," testimonial out-of-court statements have two critical components. First, to be testimonial the statement must be made with some degree of formality or solemnity. Second, the statement is testimonial only if its primary purpose pertains in some fashion to a criminal prosecution.' [Citation.]" (People v. Edwards (2013) 57 Cal.4th 658, 705.) Not all statements made to a police officer are necessarily testimonial. (Davis v. Washington, supra, 547 U.S. at p. 828.)