title: How can I sort a Map based upon on the size of its Collection values?
body: <p>I have a <code>HashMap</code> like this:</p>
  
  <pre><code>Map&lt;String, List&lt;String&gt;&gt; map = new HashMap&lt;&gt;();
  
  map.put("USA", Arrays.asList("CA","IA","IL"));
  map.put("India", Arrays.asList("MUM","CAL"));
  map.put("Canada", Arrays.asList("TOR"));
  </code></pre>
  
  <p>I want to sort the map depending on the size of the list value, in ascending order. How can I do that?</p>
  
  <p>In this case, I would like the keys to be ordered Canada, India, USA.</p>