code: def walk(self, top, topdown=True, ignore_file_handler=None):
          
  
          def onerror(e):
              raise e
  
          for root, dirs, files in dvc_walk(
              os.path.abspath(top),
              topdown=topdown,
              onerror=onerror,
              ignore_file_handler=ignore_file_handler,
          ):
              yield os.path.normpath(root), dirs, files
docs: Directory tree generator.
  
          See `os.walk` for the docs. Differences:
          - no support for symlinks
          - it could raise exceptions, there is no onerror argument