def METHOD_NAME():
    assert process_parts(
        parts_yaml_data={
            "no-grammar": {
                "source": "source-foo",
                "build-environment": ["env-foo"],
                "build-packages": ["build-pkg-foo"],
                "stage-packages": ["stage-pkg-foo"],
                "build-snaps": ["build-snap-foo"],
                "stage-snaps": ["stage-snap-foo"],
            },
            "grammar": {
                "source": [
                    {
                        "on amd64": "source-foo",
                    },
                ],
                "build-environment": [
                    {
                        "on amd64": ["env-foo"],
                    },
                ],
                "build-packages": [
                    {
                        "on amd64": ["build-pkg-foo"],
                    },
                ],
                "stage-packages": [
                    {
                        "on amd64": ["stage-pkg-foo"],
                    },
                ],
                "build-snaps": [
                    {
                        "on amd64": ["build-snap-foo"],
                    },
                ],
                "stage-snaps": [
                    {
                        "on amd64": ["stage-snap-foo"],
                    },
                ],
            },
        },
        arch="amd64",
        target_arch="amd64",
    ) == {
        "no-grammar": {
            "source": "source-foo",
            "build-environment": ["env-foo"],
            "build-packages": ["build-pkg-foo"],
            "stage-packages": ["stage-pkg-foo"],
            "build-snaps": ["build-snap-foo"],
            "stage-snaps": ["stage-snap-foo"],
        },
        "grammar": {
            "source": "source-foo",
            "build-environment": ["env-foo"],
            "build-packages": ["build-pkg-foo"],
            "stage-packages": ["stage-pkg-foo"],
            "build-snaps": ["build-snap-foo"],
            "stage-snaps": ["stage-snap-foo"],
        },
    }