code: def list_files(directory):
      '''
      Return a list of all files found under directory (and its subdirectories)
      '''
      ret = set()
      ret.add(directory)
      for root, dirs, files in safe_walk(directory):
          for name in files:
              ret.add(os.path.join(root, name))
          for name in dirs:
              ret.add(os.path.join(root, name))
  
      return list(retf list_files(directory):
      '''
      Return a list of all files found under directory (and its subdirectories)
      '''
      ret = set()
      ret.add(directory)
      for root, dirs, files in safe_walk(directory):
          for name in files:
              ret.add(os.path.join(root, name))
          for name in dirs:
              ret.add(os.path.join(root, name))
  
      return list(ret)
docs: Return a list of all files found under directory (and its subdirectories)