How to use the pyscaffold.api.helpers.ensure function in PyScaffold

def test_ensure_overriden():
    # When the original structure contains a leaf
    structure = {"a": {"b": "0"}}
    # that is overridden using the ensure method,
    structure = helpers.ensure(structure, Path("a", "b"), content="1")
    # and the file content should be overridden
    assert structure["a"]["b"] == "1"

def add_files(struct, opts):
        nov, ncr = helpers.NO_OVERWRITE, helpers.NO_CREATE
        struct = helpers.ensure(struct, "proj/tests/file0", "new")
        struct = helpers.ensure(struct, "proj/tests/file1", "new", nov)
        struct = helpers.ensure(struct, "proj/tests/file2", "new", ncr)
        struct = helpers.merge(
            struct,
            {
                "proj": {
                    "tests": {
                        "file3": ("new", nov),
                        "file4": ("new", ncr),
                        "file5": ("new", None),
                        "file6": "new",
                    }
                }
            },
        )

        return struct, opts

def add_files(struct, opts):
        nov, ncr = helpers.NO_OVERWRITE, helpers.NO_CREATE
        struct = helpers.ensure(struct, "proj/tests/file0", "new")
        struct = helpers.ensure(struct, "proj/tests/file1", "new", nov)
        struct = helpers.ensure(struct, "proj/tests/file2", "new", ncr)
        struct = helpers.merge(
            struct,
            {
                "proj": {
                    "tests": {
                        "file3": ("new", nov),
                        "file4": ("new", ncr),
                        "file5": ("new", None),
                        "file6": "new",
                    }
                }
            },
        )

Args:
        struct (dict): project representation as (possibly) nested
            :obj:`dict`.
        opts (dict): given options, see :obj:`create_project` for
            an extensive list.

    Returns:
        struct, opts: updated project representation and options
    """
    # let the markdown extension do its job first
    struct, opts = MarkDown("markdown").markdown(struct, opts)

    file_path = [opts["project"], "README.md"]
    struct = helpers.reject(struct, file_path)
    readme = templates.readme_md(opts)
    struct = helpers.ensure(struct, file_path, readme, helpers.NO_OVERWRITE)
    return struct, opts

Returns:
        struct, opts: updated project representation and options
    """
    gitignore_all = templates.gitignore_all(opts)

    path = [opts["project"], "data", ".gitignore"]
    struct = helpers.ensure(
        struct, path, templates.gitignore_data(opts), helpers.NO_OVERWRITE
    )
    for folder in ("external", "interim", "preprocessed", "raw"):
        path = [opts["project"], "data", folder, ".gitignore"]
        struct = helpers.ensure(struct, path, gitignore_all, helpers.NO_OVERWRITE)

    path = [opts["project"], "notebooks", "template.ipynb"]
    template_ipynb = templates.template_ipynb(opts)
    struct = helpers.ensure(struct, path, template_ipynb, helpers.NO_OVERWRITE)

    path = [opts["project"], "scripts", "train_model.py"]
    train_model_py = templates.train_model_py(opts)
    struct = helpers.ensure(struct, path, train_model_py, helpers.NO_OVERWRITE)

    path = [opts["project"], "models", ".gitignore"]
    struct = helpers.ensure(struct, path, gitignore_all, helpers.NO_OVERWRITE)

    path = [opts["project"], "references", ".gitignore"]
    struct = helpers.ensure(struct, path, "", helpers.NO_OVERWRITE)

    path = [opts["project"], "reports", "figures", ".gitignore"]
    struct = helpers.ensure(struct, path, "", helpers.NO_OVERWRITE)

    path = [opts["project"], "environment.yaml"]
    environment_yaml = templates.environment_yaml(opts)

path = [opts["project"], "notebooks", "template.ipynb"]
    template_ipynb = templates.template_ipynb(opts)
    struct = helpers.ensure(struct, path, template_ipynb, helpers.NO_OVERWRITE)

    path = [opts["project"], "scripts", "train_model.py"]
    train_model_py = templates.train_model_py(opts)
    struct = helpers.ensure(struct, path, train_model_py, helpers.NO_OVERWRITE)

    path = [opts["project"], "models", ".gitignore"]
    struct = helpers.ensure(struct, path, gitignore_all, helpers.NO_OVERWRITE)

    path = [opts["project"], "references", ".gitignore"]
    struct = helpers.ensure(struct, path, "", helpers.NO_OVERWRITE)

    path = [opts["project"], "reports", "figures", ".gitignore"]
    struct = helpers.ensure(struct, path, "", helpers.NO_OVERWRITE)

    path = [opts["project"], "environment.yaml"]
    environment_yaml = templates.environment_yaml(opts)
    struct = helpers.ensure(struct, path, environment_yaml, helpers.NO_OVERWRITE)

    path = [opts["project"], "requirements.txt"]
    struct = helpers.reject(struct, path)

    path = [opts["project"], "configs", ".gitignore"]
    struct = helpers.ensure(struct, path, "", helpers.NO_OVERWRITE)
    return struct, opts