code: def validate_fontsize(s):
      fontsizes = [
          "xx-small",
          "x-small",
          "small",
          "medium",
          "large",
          "x-large",
          "xx-large",
          "smaller",
          "larger",
      ]
      if isinstance(s, six.string_types):
          s = s.lower()
      if s in fontsizes:
          return s
      try:
          return float(s)
      except ValueError:
          raise ValueError(
              "%s is not a valid font size. Valid font sizes "
              "are %s." % (s, ", ".join(fontsizes))
          )
  
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 25 for calling a global function with example usage: validate_fontsize(s) and returns: s, float