public Set<AbsoluteRecordId> getAbsoluteReferrers(AbsoluteRecordId record, SchemaId vtag, SchemaId sourceField)
throws LinkIndexException, InterruptedException {
long before = System.currentTimeMillis();
try {
Query query = new Query();
query.addEqualsCondition("target", record.toBytes());
if (vtag != null) {
query.addEqualsCondition("vtag", vtag.getBytes());
}
if (sourceField != null) {
query.addEqualsCondition("sourcefield", sourceField.getBytes());