title: Adding Map to collection of maps
body: <p>I have collection of maps.</p>
  
  <pre><code>Collection&lt;Map&lt;String,Object&gt;&gt; xyz = (Collection&lt;Map&lt;String,Object&gt;&gt;) someMethod();
  xyz.add(new HashMap&lt;&gt;());
  </code></pre>
  
  <p>If I try to add another map to this collection it gives me run time exception as</p>
  
  <p>UnsupportedOperation.</p>
  
  <p>What can be done?</p>