export default function(namespace) {
  const StringElement = namespace.getElementClass('string');
  const ArrayElement = namespace.getElementClass('array');

  ArrayElement.prototype.__defineGetter__('copy', function() {
    return this.children((item) => item.element === 'copy');
  });

  namespace.register('array', ArrayElement);

  class Copy extends StringElement {
    constructor() {
      super(...arguments);
      this.element = 'copy';
    }

    get contentType() {
      return this.attributes.getValue('contentType');
    }

    set contentType(value) {
      this.attributes.set('contentType', value);
    }
  }

  namespace.register('copy', Copy);
}

@@ -286,54 +286,8 @@
 );%0A%0A
-  namespace.register('array', ArrayElement);%0A%0A
   cl

Remove unnecessary registration