def METHOD_NAME(self):
    url = "/api/2/collections/%s/xref" % self.residents.id
    res = self.client.post(url)
    assert res.status_code == 403, res
    _, headers = self.login("outsider")
    res = self.client.post(url, headers=headers)
    assert res.status_code == 403, res
    _, headers = self.login("creator")
    res = self.client.post(url, headers=headers)
    assert res.status_code == 202, res
    res = self.client.get(url, headers=headers)
    assert res.status_code == 200, res
    assert res.json["total"] == 2, res.json