What is the test for whether a plaintiff can bring an unlawful detainer claim?

The most that can be said about the tenants' theory is that their action in suing the landlords arguably "triggered" the unlawful detainer complaint. "[T]hat a cause of action arguably may have been 'triggered' by protected activity does not entail that it is one arising from such. [citation.] In the anti-SLAPP context, the critical consideration is whether the cause of action is based on the defendant's protected free speech or petitioning activity." (Navellier v. Sletten (2002) 29 Cal.4th 82, 89.)