def to_csv(format = :long)
      output = ''
      
      # build the headers
      output = to_csv_header(format)

      # get the data from each point
      @points.each do |point|
        output += point.to_csv(format) + "\n"
      end
      
      return output
    end
def to_csv(format = :long)
      output = ''
      
      # build the headers
      output = to_csv_header(format)

      # get the data from each point
      @points.each do |point|
        output += point.to_csv(format) + "\n"
      end
      
      return output
    end
output important data to CSV, ignoring all the specific data about this dataset
 (total_results, start_date) and just output the data from the points