How to use the mappyfile.update function in mappyfile

def test_update_delete_root_object():
    d1 = {"__type__": "layer", "name": "Unrated", "styles": [{"__type__": "style", "color": "#888888"}]}
    d2 = {"__delete__": True}
    d = mappyfile.update(d1, d2)
    output = mappyfile.dumps(d)
    assert output == ""

def test_update_add_item():
    d1 = {"__type__": "layer", "name": "Unrated", "styles": [{"__type__": "style", "color": "#888888"}]}
    d2 = {"name": "Unrated", "styles": [None, {"__type__": "style", "color": [0, 0, 255]}]}
    d = mappyfile.update(d1, d2)
    output = mappyfile.dumps(d)
    print(output)
    assert d["styles"][1]["color"] == [0, 0, 255]

NAME "LayerNew"
            TYPE POINT
            CLASS
                NAME "Class1"
                COLOR 0 0 255
            END
            CLASS
                NAME "Class2"
                COLOR 0 0 0
            END
        END
    END
    """

    d2 = mappyfile.loads(s2)
    d = mappyfile.update(d1, d2)

    output = mappyfile.dumps(d)
    print(output)

def test_update_delete_dict():
    d1 = {"__type__": "layer", "name": "Unrated", "metadata": {"__type__": "metadata", "key1": "val1"}}
    print(mappyfile.dumps(d1))
    d2 = {"metadata": {"__delete__": True}}
    d = mappyfile.update(d1, d2)
    output = mappyfile.dumps(d)
    print(output)
    assert "metadata" not in d.keys()

def test_update_list():
    d1 = {"__type__": "layer", "name": "Unrated", "styles": [{"__type__": "style", "color": "#888888"}]}
    d2 = {"name": "Unrated", "styles": [{"color": [255, 255, 0]}]}
    d = mappyfile.update(d1, d2)
    output = mappyfile.dumps(d)
    print(output)
    assert d["styles"][0]["color"] == [255, 255, 0]

def test_update_list_second_item():
    # test that a None type can be passed
    d1 = {"__type__": "layer", "name": "Unrated", "styles": [{"__type__": "style", "color": "#888888"}, {"__type__": "style", "color": "#888888"}]}
    d2 = {"name": "Unrated", "styles": [None, {"color": [255, 255, 0]}]}
    d = mappyfile.update(d1, d2)
    output = mappyfile.dumps(d)
    print(output)
    assert d["styles"][1]["color"] == [255, 255, 0]

def test_update_delete():
    d1 = {"__type__": "layer", "name": "Unrated", "styles": [{"__type__": "style", "color": "#888888"}]}
    d2 = {"name": "Unrated", "styles": [{"__delete__": True}]}
    d = mappyfile.update(d1, d2)
    output = mappyfile.dumps(d)
    print(output)
    assert len(d["styles"]) == 0