def METHOD_NAME(repo):
    assert [line.rstrip() for line in _show_mermaid(repo.index.graph).splitlines()] == [
        "flowchart TD",
        "\tnode1[\"stage: '1'\"]",
        "\tnode2[\"stage: '2'\"]",
        "\tnode3[\"stage: '3'\"]",
        "\tnode4[\"stage: '4'\"]",
        "\tnode5[\"stage: 'a.dvc'\"]",
        "\tnode6[\"stage: 'b.dvc'\"]",
        "\tnode3-->node4",
        "\tnode5-->node1",
        "\tnode5-->node3",
        "\tnode5-->node4",
        "\tnode6-->node2",
        "\tnode6-->node3",
    ]