In Turner v. Anheuser-Busch, Inc. (1994) 7 Cal. 4th 1238, the Supreme Court traced the development of the constructive discharge doctrine from cases decided under the National Labor Relations Act, through federal employment discrimination cases, and into state law wrongful discharge cases. (Turner, supra, 7 Cal. 4th at p. 1246.) The opinion then traced the development of the standard in the appellate courts of California, noting there were two primary aspects necessary for a finding of constructive discharge: first, there must be intolerable working conditions; second, the employer must in some manner be held to knowledge of the conditions. ( Id. at p. 1251.) As to the second issue, the Turner court modified the law as it had been established by the Court of Appeal. Rejecting liability based on constructive knowledge, the Turner opinion held that the employer must "either intentionally create or knowingly permit" the intolerable conditions in order to be held liable. (Turner, supra, 7 Cal. 4th at p. 1251.) As to the first issue, however, Turner reaffirmed the "intolerable conditions" requirement in the same terms as it had been developed in the federal courts and in the California Court of Appeal: "The essence of the test is whether, under all the circumstances, the working conditions are so unusually adverse that a reasonable employee in plaintiff's position ' " 'would have felt compelled to resign.' "" (Turner, supra, 7 Cal. 4th at p. 1247.) More specifically, "the conditions giving rise to the resignation must be sufficiently extraordinary and egregious to overcome the normal motivation of a competent, diligent, and reasonable employee to remain on the job to earn a livelihood and to serve his or her employer. The proper focus is on whether the resignation was coerced, not whether it was simply one rational option for the employee." ( Id. at p. 1246.) The Turner opinion gives some examples of what does not constitute constructive discharge: "Adverse working conditions must be unusually 'aggravated' or amount to a 'continuous pattern' before the situation will be deemed intolerable. In general, 'single, trivial, or isolated acts of misconduct are insufficient' to support a constructive discharge claim. . . . Moreover, a poor performance rating or a demotion, even when accompanied by reduction in pay, does not by itself trigger a constructive discharge." ( Turner, supra, 7 Cal. 4th at p. 1247.) In Turner v. Anheuser-Busch, Inc. (1994) the court described the severity of the conditions necessary to constitute constructive discharge. "The conditions giving rise to the resignation must be sufficiently extraordinary and egregious to overcome the normal motivation of a competent, diligent, and reasonable employee to remain on the job to earn a livelihood and to serve his or her employer. The proper focus is on whether the resignation was coerced, not whether it was simply one rational option for the employee.. . . In order to amount to a constructive discharge, adverse working conditions must be unusually 'aggravated' or amount to a 'continuous pattern' before the situation will be deemed intolerable." (Turner v. Anheuser-Busch, Inc., supra, 7 Cal. 4th at pp. 1246-1247.) The ultimate issue is "'whether a reasonable person faced with the allegedly intolerable employer actions or conditions of employment would have no reasonable alternative except to quit." (Id. at p. 1248.)