def setup_sdk_logging(logfile=None, loglevel=logging.INFO):
logging.root.setLevel(logging.DEBUG)<EOL>logging.root.addHandler(logging.NullHandler())<EOL>if logfile:<EOL><INDENT>fh = logging.FileHandler(logfile)<EOL>fh.setLevel(loglevel)<EOL>fh.setFormatter(get_default_log_formatter())<EOL>logging.root.addHandler(fh)<EOL><DEDENT>
Setup a NullHandler to the root logger. If ``logfile`` is passed,
additionally add a FileHandler in ``loglevel`` level.

Args:
    logfile(str): A path to setup a log file.
    loglevel(int): :mod:`logging` log level.

Returns:
    None