title: Passing arguments to ES6 class module in SystemJS
body: <p>I am experimenting with SystemJS and have run into some problems when trying to pass arguments to my exported Class.</p>
  
  <p>Inlined into my html I have the following:</p>
  
  <pre><code>&lt;script&gt;
      System.import('modules/accordion.js').then(function(module){
          module.accordion('HELLO THERE');
      });
  &lt;/script&gt;
  </code></pre>
  
  <p>The accordion.js file contains the following class:</p>
  
  <pre><code>class Accordion {
      constructor(message) {
          this.message = message;
          this.buildAccordion();
      }
      buildAccordion() {
          console.log(this.message);
      }
  }
  
  export var accordion = new Accordion();
  </code></pre>
  
  <p>This file is pre-transpiled with babel before being imported by SystemJS.</p>
  
  <p>The resulting console log contains <code>undefined</code>. How do i properly pass the arguments to this function?</p>