如何从Google Cloud text- to -speech API获取SSML <mark>时间戳

from google.cloud import texttospeech

def synthesize_ssml_timestamp(ssml_text):
    client = texttospeech.TextToSpeechClient()

    input_text = texttospeech.SynthesisInput(ssml=ssml_text)

    voice = texttospeech.VoiceSelectionParams(
        language_code="en-US", ssml_gender=texttospeech.SsmlVoiceGender.NEUTRAL
    )

    audio_config = texttospeech.AudioConfig(
        audio_encoding=texttospeech.AudioEncoding.MP3
    )

    response = client.synthesize_speech(
        input=input_text, voice=voice, audio_config=audio_config
    )

    # 处理API响应，提取出生成的语音文件或者音频流
    # ...

# 构建包含SSML时间戳的输入文本
ssml_text = """
<speak>
  This is an example of SSML with a timestamp.
  The current time is <mark name="timestamp"/>. 
</speak>
"""

# 调用函数进行API请求
synthesize_ssml_timestamp(ssml_text)