<http://schema.org/description>
"\u7B2C31\u56DE\u306B\u7D9A\u3044\u3066\uFF0C\u4ECA\u56DE\u306FMongoDB\u3092Ruby\u304B\u3089\u4F7F\u3046\u65B9\u6CD5\u3092\u3054\u7D39\u4ECB\u3057\u307E\u3059\u3002"^^<http://www.w3.org/2001/XMLSchema#string>
<http://gihyo.jp/dev/serial/01/ruby/0033>