{
    "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
    "data": {
        "name": "source",
        "values": []
    },
    "encoding": {
        "x": {
            "field": "cat",
            "type": "nominal"
        },
        "y": {
            "field": "val",
            "type": "quantitative"
        }
    },
    "mark": "bar"
}