What is the legal test for a murder committed by means of torture?

One of the prosecution's theories of first degree murder was murder committed by means of torture. ( 189.) To establish this theory of first degree murder, the prosecution must prove "(1) acts causing death that involve a high degree of probability of the victim's death; and (2) a willful, deliberate, and premeditated intent to cause extreme pain or suffering for the purpose of revenge, extortion, persuasion, or for any other sadistic purpose." (

[393 P.3d 49]

People v. Cook (2006) 39 Cal.4th 566, 602, 47 Cal.Rptr.3d 22, 139 P.3d 492.)