s, <code>nil</code> is just for compatibility with <code>IO</code>.</p>

<pre class="ruby"><span class="ruby-comment">#io</span>
<span class="ruby-comment">#to_io</span>
<span class="ruby-comment">#stat</span>
<span class="ruby-comment">#external_encoding</span>
<span class="ruby-comment">#transcode_options</span>
<span class="ruby-comment">#pos</span>
<span class="ruby-comment">#tell</span>
</pre>

<p>See {<code>IO</code><a href="https://ruby-doc.org/core/IO.html">}</a> docs.</p>

<pre class="ruby"><span c