docs: function runProtractorAoT(appDir, outputFile) {
    fs.appendFileSync(outputFile, '++ AoT version ++\n');
    const aotBuildSpawnInfo = spawnExt('yarn', ['build:aot'], {cwd: appDir});
    let promise = aotBuildSpawnInfo.promise;
  
    const copyFileCmd = 'copy-dist-files.js';
    if (fs.existsSync(appDir + '/' + copyFileCmd)) {
      promise = promise.then(() => spawnExt('node', [copyFileCmd], {cwd: appDir}).promise);
    }
    const aotRunSpawnInfo = spawnExt('yarn', ['serve:aot'], {cwd: appDir}, true);
    return runProtractorSystemJS(promise, appDir, aotRunSpawnInfo, outputFile);
  }