{
    "expr": "$sift(λ($v, $k){$k ~> /^A/})",
    "dataset": "dataset1",
    "bindings": {},
    "result": {
        "Age": 28,
        "Address": {
            "Street": "Hursley Park",
            "City": "Winchester",
            "Postcode": "SO21 2JN"
        }
    }
}