::: chartjs 气泡图案例
```json
{
  "type": "bubble",
  "data": {
    "datasets": [
      {
        "label": "第一个数据集",
        "data": [
          { "x": 20, "y": 30, "r": 15 },
          { "x": 40, "y": 10, "r": 10 }
        ],
        "backgroundColor": "rgb(255, 99, 132)"
      }
    ]
  }
}
```
:::