title: How to create a Pojo Class for Map Under Map, For firestore database
body: <p>I got success in uploading a nexted map into firestore database like</p>
  
  <pre><code> Map&lt;String, Map&lt;String,Map&lt;String,Map&lt;String,Boolean&gt;&gt;&gt;&gt; Fleet = new HashMap&lt;&gt;();
  </code></pre>
  
  <p>But I am not able to retrieve this map Task method.
  I do not understand how to create an object for this kind of map.</p>
  
  <ul>
  <li>MainItem
      - SubItem --
            Item: Key - True/False
  This is the structure in firebase firestore database.</li>
  </ul>
  
  <p>Kindly help me to solve this problem.</p>