In People v. Roberto V. (2001) 93 Cal.App.4th 1350, the trial court had conducted no evidentiary inquiry whatsoever into the competency of the four-year-old declarant, but merely assumed the child was incompetent to testify due to her age. (Id. at pp. 1368-1369, 1375.) While the appellate court in Roberto V. held this failure to conduct an evidentiary hearing was an abuse of discretion, the court did not hold or even suggest that the only acceptable evidence of competency to be obtained at such a hearing would have to come from the child witness under scrutiny.