code: def update_savefig_format(value):
      # The old savefig.extension could also have a value of "auto", but
      # the new savefig.format does not.  We need to fix this here.
      value = validate_string(value)
      if value == "auto":
          value = "png"
      return value
  
imports: from __future__ import absolute_import, division, print_function
  import six
  from functools import reduce
  import operator
  import os
  import warnings
  import re
  from matplotlib import cbook, testing
  from matplotlib.cbook import mplDeprecation, deprecated, ls_mapper
  from matplotlib.fontconfig_pattern import parse_fontconfig_pattern
  from matplotlib.colors import is_color_like
  from cycler import Cycler, cycler
label_desc: Use image node_id 28 for calling a global function with example usage: update_savefig_format(value) and returns: value