def METHOD_NAME(self):
    mapping = model.make_mapping(
        {
            "csv_url": "http://pets.com",
            "entities": {"test": {"schema": "Person", "key": "id"}},
        }
    )
    for ent in mapping.entities:
        seed = ent.seed.hexdigest()
        assert seed == sha1(b"").hexdigest(), seed
    entities = mapping.map({})
    assert len(entities) == 0, entities.keys()
    entities = mapping.map({"id": "foo"})
    assert len(entities) == 1, entities.keys()
    ent0 = entities.get("test")
    assert ent0.id == sha1(b"foo").hexdigest(), ent0