apollo-client/src/main/java/com/ctrip/framework/apollo/internals/LocalFileConfigRepository.java/LocalFileConfigRepository/checkLocalConfigCacheDir
class LocalFileConfigRepository:  private void checkLocalConfigCacheDir(File baseDir) {
    if (baseDir.exists()) {
      return;
    }
    Transaction transaction = Tracer.newTransaction("Apollo.ConfigService", "createLocalConfigDir");
    transaction.addData("BaseDir", baseDir.getAbsolutePath());
    try {
      Files.createDirectory(baseDir.toPath());
      transaction.setStatus(Transaction.SUCCESS);
    } catch (IOException ex) {
      ApolloConfigException exception =
          new ApolloConfigException(
              String.format("Create local config directory %s failed", baseDir.getAbsolutePath()),
              ex);
      Tracer.logError(exception);
      transaction.setStatus(exception);
      logger.warn(
          "Unable to create local config cache directory {}, reason: {}. Will not able to cache config file.",
          baseDir.getAbsolutePath(), ExceptionUtil.getDetailMessage(ex));
    } finally {
      transaction.complete();
    }
  }