* of tasks submitted by {@code invokeAll} or {@code invokeAny}, tasks will run serially on the
   * calling thread. Tasks are run to completion before a {@code Future} is returned to the caller
   * (unless the executor has been shutdown).
   *
   * <p>The returned executor is backed by the executor returned by {@link
   * MoreExecutors#newDirectExecutorService} and subject to the same constraints.
   *

    public Map<String, String> getUserProperties() {
        return userProperties;
    }

    /**
     * Sets the user properties to use for interpolation and profile activation. The user properties have been
     * configured directly by the user on his discretion, e.g. via the {@code -Dkey=value} parameter on the command
     * line.
     *
     * @param userProperties The user properties, may be {@code null}.

        service.startAsync();
      } catch (IllegalStateException e) {
        // This can happen if the service has already been started or stopped (e.g. by another
        // service or listener). Our contract says it is safe to call this method if
        // all services were NEW when it was called, and this has already been verified above, so we
        // don't propagate the exception.

        service.startAsync();
      } catch (IllegalStateException e) {
        // This can happen if the service has already been started or stopped (e.g. by another
        // service or listener). Our contract says it is safe to call this method if
        // all services were NEW when it was called, and this has already been verified above, so we
        // don't propagate the exception.

* `write(data)`: Escribe `data` (`str` o `bytes`) en el archivo.
* `read(size)`: Lee `size` (`int`) bytes/caracteres del archivo.
* `seek(offset)`: Va a la posición de bytes `offset` (`int`) en el archivo.
    * Por ejemplo, `await myfile.seek(0)` iría al inicio del archivo.
    * Esto es especialmente útil si ejecutas `await myfile.read()` una vez y luego necesitas leer el contenido nuevamente.

`UploadFile` 支持以下 `async` 方法，（使用内部 `SpooledTemporaryFile`）可调用相应的文件方法。

* `write(data)`：把 `data` （`str` 或 `bytes`）写入文件；
* `read(size)`：按指定数量的字节或字符（`size` (`int`)）读取文件内容；
* `seek(offset)`：移动至文件 `offset` （`int`）字节处的位置；
    * 例如，`await myfile.seek(0) ` 移动到文件开头；
    * 执行 `await myfile.read()` 后，需再次读取已读取内容时，这种方法特别好用；
* `close()`：关闭文件。

因为上述方法都是 `async` 方法，要搭配「await」使用。

例如，在 `async` *路径操作函数* 内，要用以下方式读取文件内容：

```Python

	eventData, eErr := target.store.Get(key)
	if eErr != nil {
		// The last event key in a successful batch will be sent in the channel atmost once by the replayEvents()
		// Such events will not exist and would've been already been sent successfully.
		if os.IsNotExist(eErr) {
			return nil
		}
		return eErr
	}

	if err := target.send(eventData); err != nil {
		if xnet.IsConnRefusedErr(err) {
			return store.ErrNotConnected

        } else {
            propertiesFile = file;
        }
        load();
    }

    /**
     * Checks if the properties file has been updated since the last load.
     *
     * @return {@code true} if the file has been updated, {@code false} otherwise.
     */
    public boolean isUpdated() {
        final long now = System.currentTimeMillis();
        if (now - lastChecked < checkInterval) {

        if (processOrdinary()) {
            return ttype;
        }
        ttype = peekc;
        return ttype;
    }

    /**
     * Returns the string that has already been read.
     *
     * @return The string that has already been read.
     */
    public String getReadString() {
        return str.substring(0, colno - 1);
    }

    private int read() {
        if (colno >= str.length()) {

        return new BuildPathSource(requireNonNull(path, "path"));
    }

    /**
     * Creates a new resolved source for the specified path and location.
     * Resolved sources are used for artifacts that have been resolved by Maven
     * from repositories (using groupId:artifactId:version coordinates) and
     * downloaded to the local repository. These sources do not support resolving
     * other sources.
     *