ChartGroupRule

An optional setting on the ChartData of the domain of a data source chart that defines buckets for the values in the domain rather than breaking out each individual value. For example, when plotting a data source chart, you can specify a histogram rule on the domain (it should only contain numeric values), grouping its values into buckets. Any values of a chart series that fall into the same bucket are aggregated based on the aggregate_type.

{
    "dateTimeRule": {
        "type": "CHART_DATE_TIME_RULE_TYPE_UNSPECIFIED"
    },
    "histogramRule": {
        "intervalSize": 0,
        "maxValue": 0,
        "minValue": 0
    }
}