code: def format_pos(self):
      pos = str(self.pos)
      if self.length_known:
          pos += "/{}".format(self.length)
      return pos
  
imports: import contextlib
  import math
  import os
  import sys
  import time
  from ._compat import _default_text_stdout
  from ._compat import CYGWIN
  from ._compat import get_best_encoding
  from ._compat import int_types
  from ._compat import isatty
  from ._compat import open_stream
  from ._compat import range_type
  from ._compat import strip_ansi
  from ._compat import term_len
  from ._compat import WIN
  from .exceptions import ClickException
  from .utils import echo
label_desc: Use image node_id 12 for calling the ProgressBar obj's underlying member method code with example usage: obj.format_pos() and returns: pos