code: def list_files(edge_path):
      """list files"""
      cmd = hadoop_fs + " -ls %s | awk '{print $8}'" % (edge_path)
      print("cmd %s" % cmd)
      pipe = subprocess.Popen(
          cmd, shell=True, stdout=subprocess.PIPE
      ).stdout
      lines = pipe.read()
      if len(lines) == 0:
          print("list_files empty")
          exit(1)
      return lines.decode().strip().split("\n")
  
file_path: PGL/apps/PGLBox/scripts/download_graph_data.py
imports: import os
  import sys
  import math
  import time
  import json
  import subprocess
  import multiprocessing
  from multiprocessing import Process
  from multiprocessing import Lock
label_desc: Use image node_id 1 for calling a global function with example usage: list_files(edge_path) and returns: lines