def METHOD_NAME(self):
    mapping = model.make_mapping(
        {
            "csv_url": "http://pets.com",
            "entities": {
                "test": {
                    "schema": "Person",
                    "key_literal": "test",
                    "key": ["a", "b"],
                }
            },
        }
    )
    entities = mapping.map({})
    assert len(entities) == 0, entities.keys()
    entities = mapping.map({"a": "aaa", "b": "bbb"})
    ent0 = entities.get("test")
    assert ent0.id == sha1(b"testaaabbb").hexdigest(), ent0
    # assert False, sha1('test').hexdigest()