title: Flutter: json.decode change the order of elements
body: <p>I get this json String from a http-request:</p>
  
  <pre><code>{"163":[{"year":"2018","downloads":253}],"162":[{"year":"2018","downloads":525}]}
  </code></pre>
  
  <p>After json.decode my map look like:</p>
  
  <pre><code>{162: [{year: 2018, downloads: 525}], 163: [{year: 2018, downloads: 253}]}
  </code></pre>
  
  <p>How can i keep the sort order in my map?</p>
  
  <p>thx</p>