::log::Logger</code> interface which consists of basically two parts:</p><ul>
<li><code>bool should_log()</code> which determines whethere a given message (based on its severity <code>enum</code> and, possibly, <code>Component</code> input) should in fact be output (for example your <code>should_log()</code> might translate the input <code>flow::log::Sev</code> to your own verbosity setting and output <code>true</code> or <code>false</code> accordingly).</li>
<li><code>void do_log()</code> which takes a poi