def METHOD_NAME(self, db_session):
    # You can't add DocumentURI's with the same claimant, uri, type and
    # content_type, even if they have different documents.
    attrs = {
        "claimant": "http://www.example.com",
        "uri": "http://www.example.com",
        "type": "foo",
        "content_type": "bar",
    }
    db_session.add(DocumentURI(**attrs, document=Document()))
    db_session.add(DocumentURI(**attrs, document=Document()))
    with pytest.raises(sa.exc.IntegrityError):
        db_session.commit()