What is the test for a jury to convict a defendant of deliberate and premeditated first degree murder?

"'A verdict of deliberate and premeditated first degree murder requires more than a showing of intent to kill. . . . "Deliberation" refers to careful weighing of considerations in forming a course of action; "premeditation" means thought over in advance. [Citations.] "The process of premeditation and deliberation does not require any extended period of time. 'The true test is not the duration of time as much as it is the extent of the reflection. Thoughts may follow each other with great rapidity and cold, calculated judgment may be arrived at quickly.' [Citations .]"' [Citation.]" (People v. Young (2005) 34 Cal.4th 1149, 1182.)