tra data</code></p>
<p><code>custom toString(): &lt;some time></code></p>

<p><code>a label: &lt;some time></code></p>
<p><code>a label: &lt;some time> extra data</code></p>
<p><code>a label: &lt;some time></code></p>

<p style="color:grey;">[some warning message indicating that a timer for label "b" does not exist]</p>

<script>
console.time();
console.timeLog();
console.timeEnd();

console.time(undefined);
console.timeLog(undefined);
console.timeLog(undefined, "extra data");
console.timeEnd(undefined);

c