code: def is_host_name(instance):
      if not isinstance(instance, str_types):
          return True
      if not _host_name_re.match(instance):
          return False
      components = instance.split(".")
      for component in components:
          if len(component) > 63:
              return False
      return True
  
file_path: catboost/contrib/python/jsonschema/py2/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 4 for calling a global function with example usage: is_host_name(instance) and returns: True, True, False, False