expected.json

{
    "uuid": "7d2e2a2c-4983-4528-b883-491748f274b6",
    "raw": "...",
    "category_id": 1000904,
    "category_path": [
        1000914,
        4188432,
        1000849,
        1000904
    ],
    "score": 3
},
{
    "uuid": "7d2e2a2c-4983-4528-b883-491748f274b6",
    "raw": "...",
    "category_id": 4223228,
    "category_path": [],
    "score": 6,
}

message.json

{
    "record": {
        "uuid": "7d2e2a2c-4983-4528-b883-491748f274b6",
        "raw": "...",
        "meta": {
            "map_collection": {
                "matches": [
                    {
                        "category_id": 1000904,
                        "category_path": [
                            1000914,
                            4188432,
                            1000849,
                            1000904,
                        ],
                        "score": 3
                    },
                    {
                        "category_id": 4223228,
                        "category_path": [],
                        "score": 6,
                    }
                ]
            }
        }
    }
}