https://code.google.com/p/go/source/browse/src/testing/testing.go?r=804cc55d6b47e49e4bf46baa4ca9ec44b9684bed#47
It says `The benchmark package will vary b.N`... but there are no `benchmark` package
currently.
It should be `The package will vary b.N` with taking account of the description in
Example section. In this context, `the package` indicates testing package.
