code: function bundle(watch, cb) {
      // prevent gulp calling done callback more than once when watching
      var firstTime = true;
  
      gulp.src('www/build/app.ts')
          .pipe(sourcemaps.init())
          .pipe(gulp_jspm({selfExecutingBundle: true}))
          .pipe(sourcemaps.write('.'))
          .pipe(gulp.dest('www/build/js'));
      // compiler.run(compileHandler);
      compileHandler();
  
      function compileHandler(err, stats) {
          if (firstTime) {
              firstTime = false;
              cb();
          }
          // print build stats and errors
          // console.log(stats.toString(statsOptions));
      }
  
      return true;
  }
docs: ****************************************************************************
  Bundle
  Transpiles source files and bundles them into build directory using JSPM.
  ****************************************************************************