What does this type declaration do? : <p>Reading through the source for <a href="https://github.com/bet365/jingo" rel="nofollow noreferrer">jingo</a>, and stubble upon this code:</p>

<pre><code>var _ io.Writer = &amp;Buffer{} // commit to compatibility with io.Writer
</code></pre>

<p>The comment is not really helping me; what does this code enforce? Assume I am familiar with interface in go.</p>

<p><a href="https://github.com/bet365/jingo/blob/master/buffer.go#L20" rel="nofollow noreferrer">source code</a></p>
