def METHOD_NAME(self):
    """ClickHouse SHALL throw an exception and disable Kerberos if more than one realm is specified in config.xml.
    """
    ch_nodes = self.context.ch_nodes
    config_path = f"kerberos/configs/{ch_nodes[0].name}/config.d/kerberos.xml"
    def modify_file(root):
        krb = root.find('kerberos')
        xml_append(krb, 'realm', 'EXAM.COM')
        return root
    check_wrong_config(node=ch_nodes[0], client=ch_nodes[2], config_path=config_path, modify_file=modify_file,
                       log_error="Multiple realm sections are not allowed")