code: def is_ipv4(instance):
      if not isinstance(instance, str_types):
          return True
      if not _ipv4_re.match(instance):
          return False
      return all(
          0 <= int(component) <= 255
          for component in instance.split(".")
      )
  
file_path: catboost/contrib/python/jsonschema/py3/jsonschema/_format.py
imports: import datetime
  import re
  import socket
  import struct
  from jsonschema.compat import str_types
  from jsonschema.exceptions import FormatError
label_desc: Use image node_id 3 for calling a global function with example usage: is_ipv4(instance) and returns: all, True, False