public String getGroupId() {
        return this.groupId;
    }
<p>
The optional group identifier of the document from the search service. Documents with the same group identifier
are grouped together and processed as one document within the service.
</p>

@return The optional group identifier of the document from the search service. Documents with the same group
        identifier are grouped together and processed as one document within the service.
aws-java-sdk-kendraranking/src/main/java/com/amazonaws/services/kendraranking/model/Document.java