2. At any time before entry of a plea of guilty to or commencement of a trial of an accusatory instrument specified in subdivision one, the district attorney may apply for an adjournment of the proceedings in the local criminal court upon the ground that he intends to present the misdemeanor charge in question to a grand jury with a view to prosecuting it by indictment in a superior court. In such case, the local criminal court must adjourn the proceedings to a date which affords the district attorney reasonable opportunity to pursue such action, and may subsequently grant such further adjournments for that purpose as are reasonable under the circumstances. Following the granting of such adjournment or adjournments, the proceedings must be as follows:

1. (a) If such charge is presented to a grand jury within the designated period and either an indictment or a dismissal of such charge results, the local criminal court is thereby divested of jurisdiction of such charge, and all proceedings in the local criminal court with respect thereto are terminated.
2. (b) If the misdemeanor charge is not presented to a grand jury within the designated period, the proceedings in the local criminal court must continue.