No party plaintiff or defendant shall be liable for the costs of any witness of the adverse party unless the witness is subpoenaed, sworn, and examined on the trial of the case or unless the plaintiff voluntarily dismisses his case before trial. No party shall be liable for the costs of more than two witnesses to the same point unless the court certifies that the question at issue was of such a character as rendered a greater number of witnesses necessary.
OCGA § 9-15-8