# File lib/big_record/base.rb, line 625
      def add_missing_cells(raw_record, requested_columns)
        requested_columns.each do |k, v|
          # don't do it for column families (e.g. attribute:)
          unless k =~ /:$/
            raw_record[k] = nil unless raw_record.has_key?(k)
          end
        end
      end