public Boolean isDefault() {
        return this.isDefault;
    }
<p>
Whether this is the default traffic distribution group created during instance replication. The default traffic
distribution group cannot be deleted by the <code>DeleteTrafficDistributionGroup</code> API. The default traffic
distribution group is deleted as part of the process for deleting a replica.
</p>
<note>
<p>
The <code>SignInConfig</code> distribution is available only on a default <code>TrafficDistributionGroup</code>
(see the <code>IsDefault</code> parameter in the <a
href="https://docs.aws.amazon.com/connect/latest/APIReference/API_TrafficDistributionGroup.html"
>TrafficDistributionGroup</a> data type). If you call <code>UpdateTrafficDistribution</code> with a modified
<code>SignInConfig</code> and a non-default <code>TrafficDistributionGroup</code>, an
<code>InvalidRequestException</code> is returned.
</p>
</note>

@return Whether this is the default traffic distribution group created during instance replication. The default
        traffic distribution group cannot be deleted by the <code>DeleteTrafficDistributionGroup</code> API. The
        default traffic distribution group is deleted as part of the process for deleting a replica.</p> <note>
        <p>
        The <code>SignInConfig</code> distribution is available only on a default
        <code>TrafficDistributionGroup</code> (see the <code>IsDefault</code> parameter in the <a
        href="https://docs.aws.amazon.com/connect/latest/APIReference/API_TrafficDistributionGroup.html"
        >TrafficDistributionGroup</a> data type). If you call <code>UpdateTrafficDistribution</code> with a
        modified <code>SignInConfig</code> and a non-default <code>TrafficDistributionGroup</code>, an
        <code>InvalidRequestException</code> is returned.
        </p>
aws-java-sdk-connect/src/main/java/com/amazonaws/services/connect/model/TrafficDistributionGroup.java