public void SaveNewPresentation(PreCreatedPresentation presentation, User user)
 {
     if (user == null)
     {
         throw new UserHaveNotRulesException();
     }
     if (new UserActions().IsUserExist(user))
     {
         throw new UserNotExistException();
     }
     if (presentation == null)
     {
         throw new PresentationNullDataException();
     }
     if (string.IsNullOrEmpty(presentation.Name))
     {
         throw new PresentationWrongNameException();
     }
     try
     {
         var createdPresentation = FormNewPresentation(presentation, user.UserId);
         TrySavePresentation(createdPresentation);
     }
     catch (Exception ex)
     {
         throw new DataBaseBaseException(ex.Message,ex);
     }
 }
 public Presentation FormNewPresentation(PreCreatedPresentation presentationData, Guid userId)
 {
     if (presentationData == null)
     {
         return null;
     }
     return new Presentation
     {
         CreateDate = DateTime.Now,
         Description = presentationData.Description,
         Name = presentationData.Name,
         PresentationId = Guid.NewGuid(),
         Tags = presentationData.Tags,
         User = new UserActions().GetUserById(userId)
     };
 }