Any person summoned as a witness in any case shall be excused by the judge from attending the court by reason of his attendance as a legislator in the General Assembly. In all civil cases it shall be the right of either party thereto to take the deposition, as provided by law, of any person desired to be used as a witness in the case who is a member of the General Assembly when the session of the General Assembly conflicts with the session of the court in which such case is to be tried.