justice or to prevent abuse of the process of the court. The basic purpose of Rule 17 is to enable the court to clarify any position or d oubt, an d the court may, either suo motu or on the request of any party, recall any witness at any stage in that regar d . This power can be exercise d at any stage of the suit. No d oubt, once the court recalls the witness for the purpose of any such clarification, the court may permit the parties to assist the court by examining the witness for the purpose of clarification require d or permitte d by the court. The power un der Rule 17 cannot be stretche d any further. The sai d power cannot be invoke d to fill up omission in the evi dence alrea dy le d by a witness. It cannot also be use d for the purpose of filling up a lacuna in the evi dence . ‘No preju dic e is cause d to either party’ is also not a permissible groun d to invoke Rule 17. No d oubt, it is a d iscretionary power of the court but to be use d only sparingly, an d in case, the court de ci des to invoke the provision, it shoul d also see that the trial is not unnecessarily protracte d on that groun d .