title: How to box double array to Double array when adding to Map?
body: <p>I want to fill up a <code>HashMap&lt;Integer,Double[]&gt;</code></p>
  
  <pre><code>Map&lt;Integer,Double[]&gt; cached_weights = new HashMap&lt;Integer,Double[]&gt;();
  </code></pre>
  
  <p>with just regular <code>int</code> and <code>double[]</code>, what's the best way to do that?</p>
  
  <p>I see <a href="https://stackoverflow.com/questions/1109988/how-do-i-convert-double-to-double"><strong>this question</strong></a>, but it answers the opposite question. </p>