title: Unable to declare an ArrayList using Code on OSX
body: <p>I'm using Code on OSX together with the .NET Core. While trying to create an ArrayList I'm getting an error that the namespace cannot be found.</p>
  
  <p>The <code>System.Collections</code> is used already. While examining what is suggested from <code>System.Collections</code> I see that not all of the methods are listed as in the documentation. </p>
  
  <p>What could be the problem? I installed the latest .NET Core from MS site.</p>