In Jensen v. Superior Court (2008) 160 Cal.App.4th 266, the court noted that when a witness is served with a subpoena but fails to appear, there is usually good cause for a continuance. But, where a witness is not subpoenaed, "his or her absence generally does not constitute good cause for the continuance of a trial. . . .This distinction between subpoenaed witnesses and unsubpoenaed witnesses rests on the question of due diligence. A prosecutor who issues subpoenas is exercising the requisite due diligence in securing the attendance of witnesses at trial, while a prosecutor who does not issue subpoenas has not made sufficient effort to ensure their presence." (Id. at p. 271.)