public UsageStatisticsSortBy withKey(UsageStatisticsSortKey key) {
        this.key = key.toString();
        return this;
    }
<p>
The field to sort the results by.
</p>

@param key
       The field to sort the results by.
@return Returns a reference to this object so that method calls can be chained together.
@see UsageStatisticsSortKey
aws-java-sdk-macie2/src/main/java/com/amazonaws/services/macie2/model/UsageStatisticsSortBy.java