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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 get_throttled_read_event_count( table_name, lookback_window_start=15, lookback_period=5):
 """ Returns the number of throttled read events during a given time frame :type table_name: str :param table_name: Name of the DynamoDB table :type lookback_window_start: int :param lookback_window_start: Relative start time for the CloudWatch metric :type lookback_period: int :param lookback_period: Number of minutes to look at :returns: int -- Number of throttled read events during the time period """

    try:
        metrics = __get_aws_metric(
            table_name,
            lookback_window_start,
            lookback_period,
            'ReadThrottleEvents')
    except BotoServerError:
        raise

    if metrics:
        throttled_read_events = int(metrics[0]['Sum'])
    else:
        throttled_read_events = 0

    logger.info('{0} - Read throttle count: {1:d}'.format(
        table_name, throttled_read_events))
    return throttled_read_events