怎么可以让brush的toolbox里面出现两个 ‘keep’, 两个'lineX'， 两个'clear',默认不管传入多少个，都只出现一个echarts 折线配置项内容和展示

业务上的需要，需要两组这样的按钮。自己定义的按钮没系统自身的功能，例如刷选，清除 保持选择

      option = {
    title: {
        text: 'Awesome Chart'
    },
    xAxis: {
        data: ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat']
    },
    yAxis: {},
    brush: {
        toolbox: ['lineX', 'keep', 'clear', 'lineX', 'keep', 'clear'],
        xAxisIndex: 'all',
        transformable: true,
        brushStyle: {
            borderWidth: 1,
            color: 'rgba(26,179,148,0.3)',
            borderColor: 'rgba(26,179,148,0.3)'
        },
        brushMode: 'single',
        brushType: 'lineX',
        removeOnClick: false,
        throttleType: 'debounce',
        throttleDelay: 300,
        inBrush: {
            colorAlpha: 1
        },
        outOfBrush: {
            colorAlpha: 1
        }
    },
    series: [{
        type: 'line',
        data: [220, 182, 191, 234, 290, 330, 310]
    }]
};