public void setRetentionPeriodUnit(String retentionPeriodUnit) {
        this.retentionPeriodUnit = retentionPeriodUnit;
    }
<p>
The unit of time in which the retention period is measured. Currently, only <code>DAYS</code> is supported.
</p>

@param retentionPeriodUnit
       The unit of time in which the retention period is measured. Currently, only <code>DAYS</code> is
       supported.
@see RetentionPeriodUnit
aws-java-sdk-recyclebin/src/main/java/com/amazonaws/services/recyclebin/model/RetentionPeriod.java