What is the test for making a motion for a mistrial before a jury has been sworn?

"For these reasons, we hold that a Wheeler motion should be made as early during the selection process as possible and that the motion for mistrial in this case, having been made after the jury was sworn, was untimely. This does not mean that a Wheeler motion made immediately before the jury is sworn necessarily will be deemed timely. We set forth only the outer limitation before which Wheeler motions must be made." (People v. Ortega, supra, 156 Cal.App.3d at pp. 69-70, 202 Cal.Rptr. 657, fn. omitted.)