how to get Default Representation in Windchill

Representation rep1 = PublishUtils.getRepresentation(epmDoc);

QueryResult queryResult = PublishUtils.getRepresentations(epmDoc);
while (queryResult.hasMoreElements()) {
Representation rep2 = (Representation) queryResult.nextElement();
if (rep2.getDefaultRepresentation()) {
    break;
}
}