<div id="app">
      <div class="chart-wrap">
        <div id="chart">
          <apexchart type=donut width=380 :options="chartOptions" :series="series" />
        </div>
      </div>
      <div class="actions">
        <button @click="randomize">RANDOMIZE</button>
        <button @click="appendData">ADD</button>
        <button @click="removeData">REMOVE</button>
        <button @click="reset">RESET</button>
      </div>
    </div>