# File lib/nanoc/base/source_data/item.rb, line 248
    def checksum
      content_checksum = if binary?
        if File.exist?(raw_filename)
          Pathname.new(raw_filename).checksum
        else
          ''.checksum
        end
      else
        @raw_content.checksum
      end

      attributes = @attributes.dup
      attributes.delete(:file)
      attributes_checksum = attributes.checksum

      content_checksum + ',' + attributes_checksum
    end