@Override
    public int hashCode() {
        int result = docId != null ? docId.hashCode() : 0;
        result = 31 * result + id2FieldUpdates.hashCode();
        result = 31 * result + fieldPathUpdates.hashCode();
        result = 31 * result + (documentType != null ? documentType.hashCode() : 0);
        return result;
    }
Returns the document type of this document update.

@return the document type of this document update
document/src/main/java/com/yahoo/document/DocumentUpdate.java