code: def process_wav(wav_rxfilename, process):
      """This function returns preprocessed wav_rxfilename.
      Args:
          wav_rxfilename:
              input
          process:
              command which can be connected via pipe, use stdin and stdout
      Returns:
          wav_rxfilename: output piped command
      """
      if wav_rxfilename.endswith("|"):
          # input piped command
          return wav_rxfilename + process + "|"
      # stdin "-" or normal file
      return "cat {0} | {1} |".format(wav_rxfilename, process)
  
imports: from __future__ import print_function
  import io
  import os
  import subprocess
  import sys
  from functools import lru_cache
  import numpy
  import soundfile
label_desc: Use image node_id 9 for calling a global function with example usage: process_wav(wav_rxfilename, process) and returns: str, unknown