code: def format(validator, format, instance, schema):
      if validator.format_checker is not None:
          try:
              validator.format_checker.check(instance, format)
          except FormatError as error:
              yield ValidationError(error.message, cause=error.cause)
  
imports: import re
  from jsonschema._utils import ensure_list, equal, extras_msg, find_additional_properties, types_msg, unbool, uniq
  from jsonschema.exceptions import FormatError, ValidationError
  from jsonschema.compat import iteritems
label_desc: Use image node_id 17 for calling a global function with example usage: format(validator, format, instance, schema) without return types