title: How to add List of objects in a Map
body: <p>I have a List and A is defined below.</p>
  
  <p>How do i add in a Map with Key as Long and values as List of Strings.</p>
  
  <pre><code>Class A
  {
  Long in;
  List&lt;String&gt; out;
  }
  Map&lt;Long,List&lt;String&gt;&gt;
  </code></pre>