public ActionResult <GroupStudentsViewModel> GroupMemberFindById(int groupMemberId)
 {
     try
     {
         if (!ModelState.IsValid)
         {
             throw new Exception(ModelState.ToString());
         }
         var groupMembers = _groupMemberService.FindById(groupMemberId);
         return(Ok(groupMembers));
     }
     catch (Exception ex)
     {
         return(BadRequest(ex.Message));
     }
 }