public String getDuration() {
        return this.duration;
    }
<p>
Duration filter value, specified in years or seconds. Specify this parameter to show only reservations for this
duration.
</p>
<p>
Valid Values: <code>1 | 3 | 31536000 | 94608000</code>
</p>

@return Duration filter value, specified in years or seconds. Specify this parameter to show only reservations
        for this duration.</p>
        <p>
        Valid Values: <code>1 | 3 | 31536000 | 94608000</code>
aws-java-sdk-rds/src/main/java/com/amazonaws/services/rds/model/DescribeReservedDBInstancesOfferingsRequest.java