What is the test for an adverse possession claim?

she prevails on the claimcan gain only the title which the owners had when the adverse possession began; and conversely, the possessor cannot, by adverse possession, acquire a greater estate than that held by the owner. ( Williams v. Sutton (1872) 43 Cal. 65, 73 [the title acquired by the adverse possessor "must of necessity correspond with that on which the disseizin operated, as he could not acquire by disseizin a greater estate than that held by" the prior owner].)⁷ Thus, where the claim of adverse possession is concerning the title to property that was subject to a previously recorded deed of trust, the possessor can only gain a corresponding titlethat is, a title subject to the prior deed of trust. Consequently, in the present case, the most that plaintiffs could ever have potentially obtained as a result of their possession initiated against the original owners was a title subject to the preexisting 2005 deed of trust.