What is the legal test for foreclosure under the California Civil Code?

"The statutory scheme can be briefly summarized as follows. Upon default by the trustor, the beneficiary may declare a default and proceed with a nonjudicial foreclosure sale (Cal. Civ. Code 2924). The foreclosure process is commenced by the recording of a notice of default and election to sell by the trustee (Cal. Civ. Code 2924). After the notice of default is recorded, the trustee must wait three calendar months before proceeding with the sale (Cal. Civ. Code 2924(b)). After the 3-month period has elapsed, a notice of sale must be published, posted and mailed 20 days before the sale and recorded 14 days before the sale (Cal. Civ. Code 2924f). The trustee may postpone the sale at any time before the sale is completed (Cal. Civ. Code 2924g(c)(1)). If the sale is postponed, the requisite notices must be given (Cal. Civ. Code 2924g(d)). The conduct of the sale, including any postponements, is governed by Civil Code section 2924g. The property must be sold at public auction to the highest bidder (Cal. Civ. Code 2924g(a))." Moeller v. Lien, 25 Cal. App. 4th 822, 830 (Cal. App. 2d Dist. 1994), citations omitted.