You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: reportable.rb
    path of file: ./repos/code_fund_ads/app/models/concerns/campaigns
    
    the code of the file until where you have to start completion: require "csv"

module Campaigns
  module Reportable
    def summary(start = nil, stop = nil)
      daily_summary_reports.scoped_by_type(nil).between(start || start_date, stop || end_date)[0]
    end


    
    def creative_worksheet(workbook, start = nil, stop = nil)
      workbook.create_worksheet(name: "Creative").tap do |worksheet|
        creative_report(start, stop).each_with_index do |row, index|
          worksheet.row(index).concat prepare_row_for_download(row)
        end
      end
    end