What is the test for "sufficiently pervasive" harassment?

" 'In determining what constitutes "sufficiently pervasive" harassment, the courts have held that acts of harassment cannot be occasional, isolated, sporadic, or trivial, rather the plaintiff must show a concerted pattern of harassment of a repeated, routine or a generalized nature. [Citation.] []... 'The required level of severity or seriousness "varies inversely with the pervasiveness or frequency of the conduct." [Citation.] "[S]imple teasing, offhand comments, and isolated incidents (unless extremely serious) will not amount to discriminatory changes in the terms and conditions of employment." [Citation.]' " (Mokler v. County of Orange, supra, 157 Cal.App.4th at p. 142.)