title: Generic arguments for serializable collections
body: <p>i have a member like this in a serializable class:</p>
  
  <pre><code>private final Map&lt;String, List&lt;T&gt;&gt; categoryMap = Maps.newHashMap();
  </code></pre>
  
  <p>the class has the following type-bounds.</p>
  
  <pre><code>&lt;T extends Serializable&gt;
  </code></pre>
  
  <p>I use findbugs to check for mistakes in my code, and it shows me that member as "not (guaranteed to be) serializable".</p>