def METHOD_NAME(self, collection):
    """Test if new index added property."""
    collection.create_index("hello")
    assert collection._indexes == {"_id_": (("_id",), {(1,)})}
    collection.create_index("hello", unique=True)
    assert collection._indexes == {
        "_id_": (("_id",), {(1,)}),
        "hello_1": (("hello",), {("there",)}),
    }