code: def validate_bool(b):
      """Convert b to a boolean or raise"""
      if isinstance(b, six.string_types):
          b = b.lower()
      if b in ("t", "y", "yes", "on", "true", "1", 1, True):
          return True
      elif b in ("f", "n", "no", "off", "false", "0", 0, False):
          return False
      else:
          raise ValueError('Could not convert "%s" to boolean' % b)
  
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 4 for calling a global function with example usage: validate_bool(b) and returns: True, False