public void setHierarchyId(String hierarchyId) {
        this.hierarchyId = hierarchyId;
    }
<p>
The ID of a hierarchy in the parent asset's model. (This can be either the actual ID in UUID format, or else
<code>externalId:</code> followed by the external ID, if it has one. For more information, see <a
href="https://docs.aws.amazon.com/iot-sitewise/latest/userguide/object-ids.html#external-id-references"
>Referencing objects with external IDs</a> in the <i>IoT SiteWise User Guide</i>.) Hierarchies allow different
groupings of assets to be formed that all come from the same asset model. For more information, see <a
href="https://docs.aws.amazon.com/iot-sitewise/latest/userguide/asset-hierarchies.html">Asset hierarchies</a> in
the <i>IoT SiteWise User Guide</i>.
</p>

@param hierarchyId
       The ID of a hierarchy in the parent asset's model. (This can be either the actual ID in UUID format, or
       else <code>externalId:</code> followed by the external ID, if it has one. For more information, see <a
       href="https://docs.aws.amazon.com/iot-sitewise/latest/userguide/object-ids.html#external-id-references">
       Referencing objects with external IDs</a> in the <i>IoT SiteWise User Guide</i>.) Hierarchies allow
       different groupings of assets to be formed that all come from the same asset model. For more information,
       see <a href="https://docs.aws.amazon.com/iot-sitewise/latest/userguide/asset-hierarchies.html">Asset
       hierarchies</a> in the <i>IoT SiteWise User Guide</i>.
aws-java-sdk-iotsitewise/src/main/java/com/amazonaws/services/iotsitewise/model/AssociateAssetsRequest.java