how to get full path of StreamWriter
<p>I'm creating <code>StreamWriter</code> using relative path.
But file doesn't appear.
To troubleshoot I want to check that full path is what I'm expecting.
So having <code>StreamWriter</code> instance how can I get the full path of the file it's going to write to?</p>

<pre><code>string fileName = "relative/path.txt"
StreamWriter sw= new StreamWriter(fileName);
// what is the full path of sw?
</code></pre>
