def handle_special_fields
      if ['referer_host', 'referer_path', 'referer_params', 'search_engine', 'search_query'].include?(params[:field])
        @items = @items.only_first_in_session
      end
      
      if ['search_engine', 'search_query'].include?(params[:field])
        @items = @items.without_nil_in params[:field]
      end
      
      if params[:field] == 'entry_path'
        params[:field] = 'path'
        @items = @items.only_first_in_session
      end
      
      super
    end
def handle_special_fields
      if ['referer_host', 'referer_path', 'referer_params', 'search_engine', 'search_query'].include?(params[:field])
        @items = @items.only_first_in_session
      end
      
      if ['search_engine', 'search_query'].include?(params[:field])
        @items = @items.without_nil_in params[:field]
      end
      
      if params[:field] == 'entry_path'
        params[:field] = 'path'
        @items = @items.only_first_in_session
      end
      
      super
    end
Handle special fields