def check(self, instance, format):
        """
        Check whether the instance conforms to the given format.

        :argument instance: the instance to check
        :type: any primitive type (str, number, bool)
        :argument str format: the format that instance should conform to
        :raises: :exc:`FormatError` if instance does not conform to format

        """

        if format in self.checkers:
            return

        func, raises = self.checkers[format]
        result, cause = None, None
        try:
            result = func(instance)
        except raises as e:
            cause = e
        if not result:
            raise FormatError(
                "%r is not a %r" % (instance, format), cause=cause,
            )
dataset/ETHPy150Open Julian/jsonschema/jsonschema/_format.py/FormatChecker.check/operator `not in` -> `in`