title: scala packages import error in IntelliJ IDEA
body: <p>I am trying to compile scala code in IntelliJ IDEA (community 2019.2) on MacBook. My scala version: 2.13.0.</p>
  
  <p>In the code:</p>
  
  <pre><code>import scala.collection.JavaConverters._
  </code></pre>
  
  <p>is greyed out and "JavaConverters._" is crossed-out.</p>
  
  <p>and </p>
  
  <pre><code> import scala.collection.JavaConversions._
  </code></pre>
  
  <p>the "JavaConversions._" is marked as RED, which means that it cannot be resolved. </p>
  
  <p>I also tried </p>
  
  <pre><code>   import scala.jdk.CollectionConverters
  </code></pre>
  
  <p>which is also greyed out (which means it is not used)</p>
  
  <p>But, I can do the same things in command line.</p>
  
  <p>Are there something I missed in IntelliJ IDEA ?</p>