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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def config(stream=sys.stderr, level=logging.NOTSET, format='%(levelname)s [%(name)s:%(lineno)s] %(message)s', file=None, file_level=None, file_format=None):
 """ Configure logging to stream and file concurrently. Allows setting a file and stream to log to concurrently with differing level if desired. Must provide either stream or file. Parameters stream: File like: Stream to write file to [Default: sys.stderr]. If none, will not write to stream. level: str|int Log level. Allowable levels are those recognized by the logging module. format: str Format string for the emitted logs. Default: 'log_level [logger_name] message' file: str Path to write log to file. If None, will not log to file. file_level: str|int|None Overwrite log level for the file. Will default to `level` if None. file_format: str|None Overwrite format of logs for file. Will default to `format` if None. """

    # It doesn't make sense to configure a logger with no handlers.
    assert file is not None or stream is not None

    # Set the formats.
    stream_format = format
    if file_format is None:
        file_format = stream_format

    # Get the log levels
    stream_level = log_level(level)
    if file_level is None:
        file_level = stream_level
    else:
        file_level = log_level(file_level)

    # Everything falls to pieces if I don't use basicConfig.
    if stream is not None:
        logging.basicConfig(stream=stream,
                            level=stream_level,
                            format=stream_format)
        # Configure file
        if file is not None:
            file = logging.FileHandler(filename=file)
            file.setLevel(file_level)
            file.setFormatter(logging.Formatter(file_format))
            logging.getLogger().addHandler(file)
    elif file is not None:
        logging.basicConfig(filename=file,
                            level=file_level,
                            format=file_format)