def METHOD_NAME(dest_dir: str) -> None:
    #
    # Load inputs.
    #
    # Load garden dataset.
    ds_garden: Dataset = paths.load_dependency("regions")
    # Read tables from regions dataset.
    regions = ds_garden["regions"][["name", "short_name", "region_type", "is_historical", "defined_by"]]
    members = ds_garden["regions"][["members"]]
    legacy_codes = ds_garden["regions"][
        [
            "cow_code",
            "cow_letter",
            "imf_code",
            "iso_alpha2",
            "iso_alpha3",
            "kansas_code",
            "legacy_country_id",
            "legacy_entity_id",
            "marc_code",
            "ncd_code",
            "penn_code",
            "unctad_code",
            "wikidata_code",
        ]
    ]
    #
    # Process data.
    #
    # Drop unneeded columns
    regions: Table = regions.drop(columns=["defined_by"])  # type: ignore
    # Create slugs for all countries and keep track of legacy slugs.
    regions["slug"] = regions["name"].astype(str).map(slugify)
    # Countries that are mappable in Grapher.
    regions["is_mappable"] = regions.index.isin(MAPPABLE_COUNTRIES)
    # Countries without country page in Grapher.
    regions["is_unlisted"] = regions.index.isin(NO_COUNTRY_PAGE)
    # Add ISO alpha 2 codes.
    regions["short_code"] = legacy_codes["iso_alpha2"]
    # Add members
    regions["members"] = (
        members["members"].astype(object).apply(lambda x: ";".join(ast.literal_eval(x)) if pd.notna(x) else "")
    )
    #
    # Save outputs.
    #
    # Create a new grapher dataset with the same metadata as the garden dataset.
    ds_grapher = create_dataset(
        dest_dir, tables=[regions], default_metadata=ds_garden.metadata, formats=["csv"], run_grapher_checks=False
    )
    # Save changes in the new grapher dataset.
    ds_grapher.save()