code: function() {
        var names = [];
        return {
          type: 'mod',
          file: 'libs',
          includeType: 'system',
          names: names,
          content: system.assets.libs.map(function(lib) { names.push(lib.name); return lib.content; }).join('\n')
        };
      }
docs: @ngdoc method
  @name ss.bundler:bundler#systemLibs
  @methodOf ss.bundler:bundler
  @function
  @description
  A single entry for all system libraries.
  
  @returns {AssetEntry} Entry