def checks(self, format, raises=()):
def _checks(func):<EOL><INDENT>self.checkers[format] = (func, raises)<EOL>return func<EOL><DEDENT>return _checks<EOL>
Register a decorated function as validating a new format.

Arguments:

    format (str):

        The format that the decorated function will check.

    raises (Exception):

        The exception(s) raised by the decorated function when an
        invalid instance is found.

        The exception object will be accessible as the
        `jsonschema.exceptions.ValidationError.cause` attribute of the
        resulting validation error.