code: def validate_animation_writer_path(p):
      # Make sure it's a string and then figure out if the animations
      # are already loaded and reset the writers (which will validate
      # the path on next call)
      if not isinstance(p, six.string_types):
          raise ValueError("path must be a (unicode) string")
      from sys import modules
  
      # set dirty, so that the next call to the registry will re-evaluate
      # the state.
      # only set dirty if already loaded. If not loaded, the load will
      # trigger the checks.
      if "matplotlib.animation" in modules:
          modules["matplotlib.animation"].writers.set_dirty()
      return p
  
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 40 for calling a global function with example usage: validate_animation_writer_path(p) and returns: p