docstr: Run as a service.
docstr_tok: ["Run","as","a","service","."]
code: def serving_method(
      self, texts, use_gpu=False, speed=1.0, vocoder="griffin-lim"
  ):
      """
      Run as a service.
      """
      wavs, sample_rate = self.synthesize(
          texts, use_gpu, speed, vocoder
      )
      wavs = [wav.tolist() for wav in wavs]
      result = {"wavs": wavs, "sample_rate": sample_rate}
      return result
  
imports: import os
  import ast
  import argparse
  import importlib.util
  import nltk
  import paddle.fluid
  import paddle.fluid.dygraph
  import paddlehub
  from paddlehub.module.module import runnable
  from paddlehub.common.utils import mkdir
  from paddlehub.module.nlp_module import DataFormatError
  from paddlehub.common.logger import logger
  from paddlehub.module.module import moduleinfo, serving
  from paddlehub.common.dir import THIRD_PARTY_HOME
  from paddlehub.common.downloader import default_downloader
label_desc: Use image node_id 5 for calling the FastSpeech obj's underlying member method code with example usage: obj.serving_method(texts, use_gpu, speed, vocoder) and returns: result