code: def cast_unicode(s, encoding=None):
      if isinstance(s, bytes):
          return decode(s, encoding)
      return s
  
file_path: catboost/contrib/python/ipython/py2/IPython/utils/py3compat.py
imports: import functools
  import os
  import sys
  import re
  import shutil
  import types
  import platform
  from .encoding import DEFAULT_ENCODING
label_desc: Use image node_id 4 for calling a global function with example usage: cast_unicode(s, encoding) and returns: s, decode