code: def doc():
      """Sanitize docstrings and add custom failure explanation"""
      return SanitizedString(_sanitize_docstring)
  
imports: import pytest
  import textwrap
  import difflib
  import re
  import sys
  import contextlib
  import platform
  import gc
label_desc: Use image node_id 7 for calling a global function with example usage: doc() and returns: SanitizedString