ember-app.js

  });

  var inputFiles = ['vendor/ember-cli/vendor-prefix.js']
    .concat(legacyFilesToAppend)
    .concat('vendor/addons.js')
    .concat('vendor/ember-cli/vendor-suffix.js');

  var vendor = stewMap(applicationJs, function(content, relativePath){
    debugger;
    if (inputFiles.indexOf(relativePath) > -1) {
      if (preventDOMGuard[relativePath]) {
        return content;
      } else {
        return ";if (document !== 'undefined') {" + content + "}";
      }
    }
  });