title: Best way to import and extend a class in ES6
body: <p>I want to create a class in one file, import and extend it in another. Something like:</p>
  
  <pre><code>/* someclass.js */
      export class SomeClass {}
  
  /* somesubclass.js */
          import SomeClass from './someclass'
          class SomeSubClass extends SomeClass {}
  </code></pre>
  
  <p>Is it possible or is there any better way to do this (e.g. using node.js <code>module.exports</code>)?</p>