title: Kotlin sort hashmap in descending order
body: <p>I have <code>val myHashMap = HashMap&lt;String, MutableList&lt;TestItem&gt;&gt;()</code>, hashmap key value is formatted date as a string for example <code>20-06-2018</code> how can I sort this hashMap in descending order?</p>
  
  <p>expected result:</p>
  
  <pre><code>22-06-2018 : []
  21-06-2018 : []
  20-06-2018 : []
  </code></pre>
  
  <p>I use this code to sort it, but result is in ascending order:</p>
  
  <pre><code>val sortedMap = myHashMap.toSortedMap(compareBy { it })
  </code></pre>