function testGetReferrent()
{
$mdr1 = Metadata_Reference::getOneFromDb(['metadata_reference_id' => 6301], $this->DB);
$mdr2 = Metadata_Reference::getOneFromDb(['metadata_reference_id' => 6302], $this->DB);
$mdr3 = Metadata_Reference::getOneFromDb(['metadata_reference_id' => 6303], $this->DB);
$mdrX = new Metadata_Reference(['metadata_reference_id' => 10001, 'DB' => $this->DB]);
$r1 = $mdr1->getReferrent();
$r2 = $mdr2->getReferrent();
$r3 = $mdr3->getReferrent();
$rX = $mdrX->getReferrent();
$this->assertEqual(6001, $r1->metadata_structure_id);
$this->assertEqual(6101, $r2->metadata_term_set_id);
$this->assertEqual(6211, $r3->metadata_term_value_id);
$this->assertEqual('UNKNOWN METADATA_TYPE: //', $rX);
}