What is the test for establishing an abandonment of a property?

[199 Cal.App.3d 1385] Abandonment is a question of fact for the trial court or the jury (Gerhard v. Stephens (1968) 68 Cal.2d 864, 890-892, 69 Cal.Rptr. 612, 442 P.2d 692) which will not be disturbed on appeal if the trial court's determination is supported by substantial evidence. (Id., at pp. 891-892, 69 Cal.Rptr. 612, 442 P.2d 692.) Abandonment hinges upon the intent of the owner to forego all future conforming uses of the property, and there must be conduct demonstrating that intent which is so decisive and conclusive as to indicate a clear intent to abandon. ( Id., at p. 889, 69 Cal.Rptr. 612, 442 P.2d 692.)