Why is a synchronized block used in this example of IntentService?
<p>The Android documentation says the following about IntentService:</p>

<blockquote>
  <p>[IntentService] creates a work queue that passes one intent at a time to your onHandleIntent() implementation, so you never have to worry about multi-threading.</p>
</blockquote>

<p>But in the example that follows, they use a synchronized block in method onHandleIntent as if it is expected to be executed simultaneously.</p>

<pre><code>protected void onHandleIntent(Intent intent) {
    synchronized (this) {
        Some operations...
    }
}
</code></pre>

<p>Why are they using synchronized here? Am I missing something?</p>
